Inquiry Activity - Ball State University



Guided Inquiry (5E Lesson) |Exploring Motion | |

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|Objectives: The students will be able to … |

|Use a motion sensor to make position versus time graphs. |

|Interpret position versus time graphs by relating an objects motion to its graph. |

|Experience Newton’s three laws of motion via hands-on investigations. |

|Identify instances where Newton’s Laws of Motion are illustrated. |

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|Standards Addressed: (Indiana Academic Science Standards) |

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|5.3.11 Investigate and describe that changes in speed or direction of motion of an object are caused by forces. Understand that the greater |

|the force, the greater the change in motion and the more massive an object, the less effect a given force will have. |

|6.2.3 Select tools, such as cameras and tape recorders, for capturing information. |

|6.2.6 Read simple tables and graphs produced by others and describe in words what they show. |

|6.5.4 Demonstrate how graphs may help to show patterns, such as trends, varying rates of change, gaps, or clusters, which can be used to |

|make predictions. |

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|Optional: (with further extensions or additions to the lesson) |

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|5.3.12 Explain that objects move at different rates, with some moving very slowly and some moving too quickly for people to see them. |

|7.3.17 Investigate that an unbalanced force, acting on an object, changes its speed or path of motion or both, and know that if the force |

|always acts towards the same center as the object moves, the object’s path may curve into an orbit. |

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Required Materials:

|Engagement (option #1) |Station 4 |

|Sewing thread (1 spool) |Boiled egg and non-boiled egg (4) |

|Ring stand with secure extended arm (1) | |

|Mass with a place to tie the thread on the top and bottom (1) |Station 5 |

|Wooden dowel or stick (1) |Magnetically levitated horizontal spinning top. (“Strobe Revolution”) |

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|Engagement (option #2) |Station 6 |

|Passport Motion Sensor (PS-2103) (6) |Sheets of 8 ½ x 11 in. paper (20) |

|Passport USB Links (PS-2100) (6) |Bowling Ball (1) |

|Reflector Paper / Board (6) |Basket Ball (1) |

| |Tennis Ball (1) |

|Station 1 | |

|Table cloth (smooth without a thick edge) (1) |Station 7 |

|Old heavy unbreakable dish and silverware (1) |Spring Scales (2+) |

|Paper plates and plastic silverware (1) | |

| |Station 8 |

|Station 2 |Bathroom scales (2) |

|Glass or plastic flask (empty soda bottle, ketchup bottle, etc…) (1) | |

|Golf tee (1) |Station 9 |

|Embroidery hoop (1) |Balloons |

| |Balloon helicopter (1) |

|Station 3 | |

|Coat hanger (1) | |

|Small blocks of wood (2) | |

Introduction:

Isaac Newton came up with three laws of motion in an attempt to describe the movement of objects. Believe it or not, for as much as students have had a life full of experience with moving and non-moving objects, they do not understand basic ideas of movement. Everyday experiences often seem to contradict Newton’s laws of motion. The idea behind Newton’s first law of motion is that “objects want to keep doing what they are doing.” If an object is at rest it wants to stay and rest, and if an object is in motion it wants to stay in motion, maintaining the same speed in the same direction. But, everyone knows that anything that is moving will “naturally” come to rest or stop over time. This is of course is due to the force of friction, but students are not aware of this. The exploration part of this activity gives students opportunities to experience events where Newton’s first law is clearly illustrated.

Newton’s second law can simply be expressed in an equation form, [pic]; the acceleration of an object is equal to the force exerted on the mass divided by the mass of the object, and the acceleration of the object is in the direction of the force on the object. Conceptually this means that the more mass an object has a greater force is required to change its motion or speed.

Newton’s third law is probably the least intuitive out of the three. It states that for every action there is an equal and opposite reaction. The word “force” can be substituted for the word “action.” So Newton’s third law can be stated for every force there is an equal and opposite force. Every student may know that the force of gravity pulls everything down toward the Earth, but every student may not know that a person standing at rest on the Earth experiences two forces: one from gravity pulling down and one from the Earth pushing back up. If just the force of gravity was acting on that person, that person would accelerate toward the Earth. This is the case when a skydiver jumps out of an airplane, there is no counter-active force, from his/her feet to the ground, to cancel out the attractive force of gravity, resulting in a rapid accleration toward the Earth below.

Engagement:

Option #1 (Time = 20minutes) **It’s a good idea to practice this before hand!**

1. Setup the apparatus as pictured in the diagram on the right. You will need to have a heavy mass for the demonstration to work properly, but it must not be too big or the string will inadvertently break under its weight. (For a simple and cheap option use three, three quarter inch washers which can be purchased from your local home improvement store for under a dollar!)

2. Ask the students which string will break first, if you pull on the bottom stick.

3. If the majority of the students think the top string will break, proceed to demonstrate by pulling fast on the stick. This will cause the bottom string to break. If the majority of the students think that the bottom string will break, pull the stick slowly downward. This will cause the top string to break first.

4. Setup up the appartus another time (you may want to have precut thread, with loops on either end, so the demonstration can be repeated multiple times in a relatively short amount of time).

5. Now ask a student to come up and try to break the other string, whichever string was not broken the first time.

6. If the student volunteer is unable to preform the task, break the other string by pulling either slowly (breaks top string) or fast (breaks the bottom string).

7. Ask the students if they noticed anything that was done differently when each of the strings were broken.

8. Ask for additional student volunteers to break the string of your choosing. Continue this process until the students catch on to the difference in technique when breaking the strings.

9. Explain to the students that knowing how objects move allows you to break either of the two strings that you wish. Tell them that throughout the next several days they will be investigating how things move and what, if any, rules the objects must follow when they move. The students will revisit this demonstration later in the lesson to try and explain the phenomena, after they have investigated the laws of motion.

Logic Behind Demonstration (Don’t tell them yet!) The bottom string breaks if the stick is pulled quickly because the of the weight’s inertia; the weight wants to stay not moving. When the stick is pulled slowly the force on the top string is equal to the force applied by your hand plus the weight of hanging mass. Since the bottom string only feels the weight applied by you hand, the top string will always break first when the stick is pulled slowly.

Option #2 PASCO Match Graph Activity (Time = 50 minutes)

Equipment needed for each group:

|Pasport Motion Sensor |Passport USB Links |(Optional) Reflector Paper / Board |

|(PS-2103) |(PS-2100) | |

Procedure:

1. Ask the students to give some examples of objects that move. Have the students try to describe the motion of the objects they mentioned. Ask them to be as specific as possible when giving their descriptions.

2. Discuss how scientists use position graphs to help describe the movement of objects. Show the students the following examples of motion and their corresponding position versus time graphs. Relevent pictures, data, and graphs for the following examples are found in separate handouts at the back of the lesson. These handouts can be copied onto transparencies for whole-class viewing.

a. (Teacher Motion) The handout contains a table of position and time data and a corresponding graph. Make 0.2 meter incremental markings on the floor from zero to two meters and demonstrate the motion displayed on the graph for the students to see. Tell the students that the value for your position is the distance you are away from your starting point. Show them the data table and graph that corresponds to the demonstrated movement. Discuss how each point on the graph corresponds to a specific position and time from the data table (point out several examples).

b. (Model Rocket Flight) Ask the students if they have ever seen a rocket take off. Ask the students what happens during the flight of a rocket from the point that it takes off to the point that it returns to the ground. Discuss the different phases of a rocket flight: liftoff, ascent, maximum height, rapid descent, parachute deployment, slow descent, and touchdown. Show the students the graph of altitude (position) versus time. Ask the students to identify what time after lift off these events happened:

i. The rocket reached its maximum height (3 sec.)

ii. The parachute was released and started to slow down the falling rocket (> 3 sec.)

iii. The rocket landed (< 25 sec.)

c. (Roller Blader on Halfpipe) Have the students watch the video and see the corresponding position (height) versus time graph. They should be viewed side by side for comparison using the Data Studio software or Power Point.

3. Launch the Pasport Motion EZ Screen by simply plugging in the Pasco motion sensor into a USB port on a computer that has the Data Studio software on it. If the program does not launch automatically double click on the file titled “EZMotion.exe”. The icon is on the right. This file can be found in the folder at the following location C:\Program Files\DataStudio\EZScreens\EZMotion.exe.

** See the next page for the opening screen**

• The opening screen of EZMotion should look this…

4. Explain to the students that they will try to create a position versus time graph by moving back and forth relative to the motion sensor. Using the EZ Screen program, demonstrate how the motion sensor will produce a graph while you are moving. With the sensor, try to reproduce the teacher motion graph that was discussed earlier so the students are able to see it created in real time.

5. Have the students complete PASCO’s Match Graph Activity. A copy of the activity can be downloaded from Pasco’s website:

6. Following the activity, discuss how these types of graphs allow us to measure and describe the motion of an object but they do not allow us to predict the motion of an object. Tell the students that over the next several days they will find out how to predict the motion of an object and they will find out if there are any rules that all objects must “obey” when they move.

Exploration: (Time = 1 - 2 days)

This portion of the activity involves many different types of stations illustrating Newton’s three laws of motion. The students cycle throught the different stations, following instructions, and answering the provided questions. These stations give students an additional wealth of experience dealing with the movement of objects. This experience will allow them to start forming ideas of how things move and will help them understand Newton’s three laws of motion.

Each station will have an instruction sheet with relevent questions that the students must answer after performing the appropriate activity. The instructions and questions for each station are include in the back of the activity (pages 18 – 26). The instructions can be laminated for repeated use. Stations one through five illustrate Newton’s first law, station six illustrates Newton’s second law, and stations seven through nine illustrate Newton’s third law. A majority of the station directions and questions were taken directly from “Cool Stuff” an online newsletter published by Arbor Scientific (Chiaverina, 1).

The lab stations do not have to be done in any specific order, so the students can be evenly divided up and assigned to any station. The students should be given five to ten minutes at each station and then move to the next. It works best if all the students move at the same time instead of each group moving when they are finished with each station. As the students perform the designated activities and answer the questions focus on the students’ ability to reason based on their observations, rather than solely evaluating students on correct responses to the questions (remember the students are just starting to form ideas of how things move and should not be expected to get everything right the first time. They are figuring it out!).

Explanation: (Time = 30 minutes)

1. Review the students experience over the last couple days, by having students volunteer to read their answers from the stations to the class. Discuss the presented answers and answer any questions that may arise.

2. Discuss how the scientist Sir Isaac Newton spent time observing the world around him and performing experiments to find out if there are any rules that objects must follow when they move. He came up with three general rules that describe why objects move the way they do. Write the following paraphrased rules on the board for students to see.

Newton’s Laws or Rules of Motion: (Paraphrased)

(Law #1) If left alone, objects will keep doing what they are currently doing. If an object is not moving, it “wants” to stay not moving; and if an object is moving, it “wants” to stay moving.

(Law #2) The greater the force (push or pull) on an object, the greater the change in motion and the more massive an object, the less effect a given force will have.

(Law #3) If something is pushed or pulled, it will push or pull right back with the exact same amount of force. (Example: If you push on the wall the wall will push back)

3. Give the students the Newton’s Laws Worksheet located near the end of the lesson and have them work in groups to match Newton’s three laws of motion to the stations that best illustrate them. They will also need to explain how the station illustrates the law / rule that was chosen. Ultimately every object at each station could illustrate any one of Newton’s three laws, but each station is is designed to best illustrate one of Newton’s three laws of motion. However, any answer could be correct as long as the students’ explain their answers properly and refer back to observations that were made. .

4. As a class, review the groups’ answers to the worksheet. Focus on students’ explanations and reasoning when they give their answers (Remember, each station could illustrate any one of Newton’s Three Laws of Motion, but one should standout) Make sure their explanations make sense.

5. Revisit the demonstration used for the engagement portion of the activity, option number one on page three. Repeat the demonstration and now have students explain why pulling fast will break the bottom string and pulling slowly will break the top string.

• (Answer) The bottom string breaks if the stick is pulled quickly because the of the weight’s inertia; the weight wants to stay not moving. When the stick is pulled slowly the force on the top string is equal to the force applied by your hand plus the weight of hanging mass. Since the bottom string only feels the weight applied by you hand, the top string will always break first when the stick is pulled slowly.

Explanation (Advanced): (Time = 90 minutes)

**If you decide to do the advanced option with your students, this should be done in place of the previous explanation section**

Newton’s 1st Law

1. Lead a discussion reviewing the activities invovled in stations one through five and discuss specific student responses to the questions from each station.

• Ask students to explain the reasoning behind their answers. “What did you observe that supports your answer?”

• Pages 14 & 15 of the activity contain the correct answers for reference.

2. Ask the students to come up with statements about how things moved at each station, based on their experience. Ask the students to refer to their experiences with specific stations to back up their stated “rule of motion” (Below are some examples of possible student responses)

• “Rule of Motion: Objects that are not moving stay that way until they are pushed by something”

• “Rule of Motion: Once you get something moving it keeps moving until you stop it”

3. Synthesize student responses into one or two statements that revolve around the concept addressed by Newton’s first law (see the introduction pages 2 & 3).

4. Tell the students that they have just discovered a rule that objects must follow during motion. Isaac Newton had the same idea, he called it the first law of motion. Introduce Newton’s first law: objects at rest tend to stay at rest and objects in motion tend to stay in motion (at a constant speed and in a constant direction), or more simply if an object is not moving it will “want” to stay not moving and if an object is moving it will “want” to stay moving.

5. Introduce the idea of inertia: the tendency of an object to continue to do what it is doing. If it is at rest it “wants” to stay that way, and if it is moving it “wants” to stay moving. Ask the students the following questions:

• Do some objects have more inertia than others? .. more of an ability to continue to do what they are doing? … more of a tendency to stay at rest or continue moving? Have several students give examples and explain them.

▪ Desired Response: “Yes, some things like large rocks, cars, or a bulldozer have a lot of inertia because they are very difficult to move or stop if they are moving. Conversely things like a ping-pong ball or a pencil do not have a lot of inertia becaue they are easy to get moving, or easy to stop once they are moving.”

• What property of an object determines the inertia of that object? Think about your previous examples. What was different about the examples you gave of objects that had a small inertia as a opposed to those that had a large inertia?

▪ Desired Response: “How much something weighs, or its mass is what determines the inertia of an object. Size does not determine the strength of an object’s ability to keep doing what it is doing. For example, a large beach ball has less inertia than a baseball which is much smaller.”

• At station one how did the situation change when you replaced the plastic plate and cup with the paper plate and light plastic cup? Why did this happen?

▪ Desired Response: “Unlike the heavy plastic plate, the paper plate did not stay on the table . This happened because the paper plate is lighter than the original plate. The force of friction of the moving table cloth underneath had more of an effect on the lighter paper plate than the heavier plate causing it to move more and fall off of the table.”

6. Revisit the demonstration used for the engagement portion of the activity (page three). Repeat the demonstration and now have students explain why pulling fast will break the bottom string and pulling slowly will break the top string.

• (Answer) The bottom string breaks if the stick is pulled quickly because the of the weights inertia; the weight wants to stay not moving. When the stick is pulled slowly the force on the top string is equal to the force applied by your hand plus the weight of hanging mass. Since the bottom string only feels the weight applied by you hand, the top string will always break first when the stick is pulled slowly.

Newton’s 2nd Law

1. Lead a discussion reviewing the activity invovled in station six and discuss specific student responses to the questions from the stations.

• Ask students to explain the reasoning behind their answers. “What did you observe that supports your answer?”

• Page 15 of the activity contains the correct answers for reference.

2. Ask the students to come up with a “rule” about how things move based on their experience of station number six. Ask the students to refer to their experiences with the station to back up their stated “rule of motion” (Below is an example of a possible student response)

• “Rule of Motion: Heavier things are harder to get moving.”

▪ “This was shown when we tried to speed up the bowling ball. We couldn’t get it to go very fast. The tennis ball and the basketball where both much faster when they crossed the finish line.”

• “Rule of Motion: Lighter things are easier to speed up.”

▪ “This was shown when we compared the speed of the tennis ball with that of the bowling ball. The tennis ball was easier to speed up than the bowling ball.”

3. Synthesize student responses into one rule that revolves around the concept addressed by Newton’s second law (see the introduction page 3).

4. Introduce Newton’s Second Law: “The greater the force (push or pull) on an object, the greater the change in motion and the more massive an object, the less effect a given force will have.”

5. Discuss the following example that illustrates Newton’s 2nd law of motion: Larger engines in a car or truck are able to give a larger push to get the vehicle moving. So a small car with a big engine can speed up quicker than the same car with a small engine. Newton’s second law also suggests that the heavier something is the harder it is to get moving or to slow down, so if you had a big engine in both a small car and a large bus which one do you think could move the fastest (Check out the diagram below)? “Can you explain why small car with a small engine could keep up with a big truck which has a big engine, even though the larger engine can push more?”

[pic]

Newton’s 3rd Law

1. Lead a discussion reviewing the activities invovled in stations seven through nine and discuss specific student responses to the questions from each station.

• Ask students to explain the reasoning behind their answers. “What did you observe that supports your answer?”

• Pages 15 & 16 of the activity contain the correct answers for reference.

2. Ask the students to come up with “rules” about how things move based on their experience of these four stations. Ask the students to refer to their experiences with specific stations to back up their stated “rule of motion” (Below are some examples of possible student responses)

• “Rule of Motion: If you push against something it will push back with the same force.”

▪ “This was shown when we pushed two bathroom scales together. Each scale had the same reading no matter how hard we pushed.”

• “Rule of Motion: When two things attract one another, they do so with the same force.”

▪ “This was shown when we brought two magnets close to one another. They both came toward eachother at identical speeds, which means they must have had the same force exerted on them.”

• “Rule of Motion: When two things pull agianst one another they do so with the same force.”

▪ “This was shown when we used the spring scales and had a small tug-of-war. No matter how hard or soft we pulled, both scales had the same reading. This shows that when two objects pull on one another they are pulling with the same amount of force.”

3. Synthesize student responses into one rule that revolves around the concept addressed by Newton’s third law (see the introduction page 3).

4. Introduce Newton’s third law: For every action there is an equal and opposite reaction. Explain that you can substitue the work “force” for “action” and it would read “for every force there is an equal and opposite force.”

5. Ask the students if they remember the definition of a force. “What is Newton’s third law with this defition?”

• “For every push or pull there is an equal and oppostie push or pull.”

6. Ask the students if they can think of a situation where this law does not hold true. Any situation that is brought up will provide an opportunity for the teacher to show that indeed there are equal forces present. Fully discuss several student responses.

• Student Response: “The Earth’s gravitational force pulls down on me causing me to be pulled toward the Earth, but I don’t pull on the Earth, otherwise the Earth would come to me.”

▪ Teacher response: “How do you know that you do not exert the same amount of force on the Earth that the Earth exerts on you? Remember the the more mass something has the more force it takes to accelerate it or move it. We will learn more about the force of gravitation later in the year, but each object exerts the same force on eachother. The reason for the attraction is different, but think about a really large magnet and a small magnet. They exert the same force on one another, but the smaller magent moves toward the larger magnet faster because it has a smaller mass. Remember what we learned yesterday concerning Newton’s second law. The acceleration of an object is determined by its mass and the force applied. The same force applied to two objects with different masses will give two different accelerations. The object with the large mass will have a small acceleration, and the object with the small mass will have a large acceleration. When you talk about the difference in mass between a human being and the earth you are talking about a factor of over ten thousand billion billion to one. So with same force exerted on each object, the acceleration will be different by that same factor.

Elaboration: (Time = 20-30 minutes)

Have the students discuss the following scenarios as a class or you may use these questions to make a worksheet. Tell the students that they must use their knowledge of Newton’s Rules or Laws of Motion to answer the following questions…

1. Why is it good to wear a seatbelt if you are in a head-on collision? Why?

• (Answer) When you are in a head-on collision the car stops suddenly when it hits the other car, if you are not wearing a seatbelt your body will “want to” keep moving, because nothing is stopping it, so it will move forward into the steering wheel or windshield, likely injuring you.

2. If you were playing football would you rather be tackled by the kicker or a linebacker? Why?

• (Answer) It would be better to be tackled by the lighter player, the kicker. The kicker would have less inertia, less of a tendency to keep moving than the heavier linebacker. It would hurt less!

3. When you jump you push down quickly on the ground. If you are pushing down, why do you go up?

• (Answer) When you push down on the ground with your legs, the ground pushes back up with the same amount of force on your legs, pushing you upwards into the air.

4. During liftoff, a rocket shoots out burning gas in the opposite direction the rocket is traveling. How does this allow a rocket to move upward?

• (Answer) If the rocket is forcing the gas downward, the gas will push back with the same amount of force in the opposite direction, propelling the rocket upward.

5. Why is it a good idea to be in your seat when a bus starts to move instead of standing up next to your seat?

• (Answer) If you are standing when the bus starts to move, your body wants to stay not moving, so you will appear to fall backwards. In reality you are just staying still and the bus is moving forward. If you are seated, when the bus begins to move the seat will take you with the bus; it will get you moving.

Evaluation:

The student assessment should be done throughout the entire activity. Students’ involvement and reasoning skills should be informally assessed during discussion and question and answer periods. The written answers from the exploration can be used as a means of formal assessment. (More formal assessment to come)

Worksheet Answers

**The student responses will probably not be filled with the same amount of physics terms and jargon included in these answers, but the main ideas should be the same.**

1. (Not with My Dishes!)

i. The dishes stayed there because the table cloth was pulled out from underneath them very fast. If the table cloth was pulled slowly, all of the dishes would have fallen on the floor. (Students may not yet have a concept of inertia so this answer is enough)

ii. The dishes moved a little bit because was some friction between the table cloth and the dishes and silverware.

iii. A smooth table cloth was used to reduce the amount of friction between the table cloth and the dishes.

iv. When the paper plate and plastic silverware was used they flew off the table when we tried to quickly remove the table cloth. The weight of the dishes and silverware did matter, the heavier the better!

2. (Tee off Time…)

i. The tee dropped into the container underneath it. This happened because the hoop was quickly taken from underneath the golf tee.

ii. When the outside of the hoop was grabbed the tee fell outside of the container. This happened because when the outside of the hoop was grabbed the hoop’s width was decreased and its momentary height was increased maintaining contact between the tee and hoop while the hoop was being moved. This caused the tee to move and miss the container when it fell. When the inside of the hoop is grabbed, its width is temporarily increased which in turn decreases its height. This temporary decrease in height of the embroidery hoop separates its surface from the bottom of the tee, allowing the hoop to be snatched from underneath the tee without moving the tee. The tee then simply drops into the open container.

3. (Looking Back…)

i. As my body spins around, the wire frame and the wood blocks remain relatively motionless; they maintain approximately the same position they started in.

ii. The apparatus barely moves because there is not much friction between someone’s head and the part of the wire frame apparatus that touches the head. The balls will not turn unless a force is applied. Apparently the force was too small to make much of a difference concerning the motion of the wire frame and the blocks of wood.

4. (Egg Spin!) Description – when the “x” egg was spun and temporarily stopped it stayed motionless after the finger that stopped it was taken off of the egg. However, when the “o” egg was spun, after a finger was used to temporarily stop the egg and then taken off, the egg started to spin again.

i. The two eggs behave differently because one of the eggs is raw and the other is not.

ii. A cook could use this knowledge to determine if an egg is raw or cooked.

5. (Revolution)

i. The spinning axle takes a long time before it comes to rest and stops spinning.

ii. If all frictional forces could be eliminated, the axle would spin indefinitely.

6. (Speed it Up!)

i. The tennis ball was moving the fastest when it crossed the finish line.

ii. The bowling ball was moving the slowest when it crossed the finish line.

iii. The tennis ball was able to be moved the fastest because it weighed the least out of the three balls.

7. (Spring Pull)

i. The readings on the scales are always the same no matter how hard you pull.

ii. We could not find a way to make one scale register a higher value than the other scale.

iii. By simply pulling on the scales, we could also not find a way to make one scale read zero and not the other.

8. (The Big Push…)

i. Similarly to station nine, the readings on these scales were also always the same.

ii. We could not come up with a way to push on the scales so one would produce a higher reading on the scale than the other.

iii. If you pull on something it will always pull back with the same amount of force and if you push on something it will always push back with the same amount of force.

9. (Up Up & Away!)

i. The helicopter is able to fly and stay up in the air because the spinning blades push down on the air consequently the air pushes back up on the blades countering and overcoming the force of gravity, allowing the helicopter to “fly” upward.

ii. The helicopter blades do push on the surrounding air. This can be inferred when you place your hand underneath the rotating blades; you can feel air being pushed down. The air must push up on the blades; this force upward on the blades, from the air, causes the helicopter’s upward motion.

iii. A helicopter would not fly in outer space where there is no atmosphere. A helicopter needs something to push down, so that something can push back up on it, keeping it from plummeting back down to Earth.

Web Sources:

1. Chiaverina, Chris. Introducing Newton’s Laws with Learning Cycles. Cool Stuff, Arbor Scientific. Volume VI 2002.

2. Match Graph. Pasco website. 2005 middle_school/october_2002/home.html

Author: Aaron Debbink

Newton’s Laws Worksheet

Names: ______________________________________________________________________

Directions: Write the number of Newton’s Law of motion that best describes the experience at each station. Explain the reason you chose that law by giving an example of what you observed.

Law #1 If left alone, objects will keep doing what they are currently doing. If an object is not moving, it “wants” to stay not moving; and if an object is moving, it “wants” to stay moving.

Law #2 The harder something is pulled or pushed the quicker its speed will increase, and if you push two objects with the same amount of force the one that weighs the least will speed up quicker.

Law #3 If something is pushed or pulled, it will push or pull right back with the exact same amount of force.

|Station #1 __________ (Not with My Dishes!) |Station #6 __________ (Speed it Up!) |

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|Explanation: |Explanation: |

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|Station #2 __________ (Tee off time…) | |

| |Station #7 __________ (Spring Scales) |

|Explanation: | |

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|Station #3 __________ (Looking Back…) | |

| |Station #8 __________ (The Big Push) |

|Explanation: | |

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|Station #4 __________ (Egg Spin) | |

| |Station #9 __________ (Balloon Helicopter) |

|Explanation: | |

| |Explanation: |

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|Station #5 __________ (Revolution) | |

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|Explanation: | |

Not with my Dishes!

Station 1

Directions: Haven’t you always wanted to try the old table cloth and dishes trick? To perform this time-honored magician’s trick, place some of the old dishes (you may want to begin with a single plate) on a smooth tablecloth. Grab both ends of the tablecloth and, without hesitation, pull the tablecloth out from under the dishes as quickly as you can. Don’t stop pulling until the table cloth is completely out from underneath the dishes!

[pic]

Questions:

i) Why did the dishes remain virtually motionless when the tablecloth was quickly pulled out from under them (assuming you were successful)?

ii) Did the dishes move at all? Why?

iii) Why was a smooth tablecloth used? What do you think would happen if a rough material like sandpaper was used?

iv) Now try it using a paper plate and plastic silverware. What happened? Did the weight of the plate and silverware matter?

Tee off time...

Station 2

Directions: Balance an embroidery hoop on the mouth of an empty container or glass soda or catsup bottle (see photo). Now place an inverted golf tee or flattened piece of chalk on the top of the hoop. Make certain that the tee is directly over the mouth of the bottle. Now take a deep breath, and remove the hoop by quickly grabbing the inside center of the hoop.

Grabbing the hoop from the inside: Grabbing the hoop from the outside:

Questions:

i) What happened to the wooden golf tee when you grabbed the hoop from the inside, pulling it away from the container? Why do you think this happened?

ii) Repeat the experiment, this time quickly grab the outside of the hoop, pulling it away from the container. What happens now? Can you explain your observation?

Looking Back...

Station 3

Directions: Balance the center point of the wire on the top of your head. Make certain that the wire frame does not come in contact with your ears. Now quickly spin around.

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Questions:

i) Describe the motion of the frame and the blocks of wood as your body spins around.

ii) Can you explain why the wire frame and the blocks of wood on your head barely budges as you move?

Egg Spin!

Station 4

Directions: In this “eggsperiment” you will use two eggs, one marked with an“O”, the other with an “X.” Spin the egg marked with an “X” on its side. Now stop the egg with your hand. Immediately after the egg stops, remove your hand. Describe what happens. Now spin the egg marked with an “O” on its side. Again stop the egg with your hand and then quickly release it. Describes what happens this time.

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Questions:

i) Why do think the two eggs behave the way they do?

ii) How could a cook make practical use of the results of this experiment?

Revolution

Station 5

Directions: Give the “Strobe Revolution” a gentle spin and observe what happens.

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Questions:

i) Once the object is spinning how long does it take before it stops moving?

ii) If all frictional forces could be eliminated, how long do you think

the axle would spin?

Speed it Up!

Station 6

Directions: Use a rolled up sheet of paper (8 ½ x 11 in.) to push each of the balls from the starting line to the finish line. Move the balls by pushing it with the rolled up sheet of paper as shown in the pictures (Nothing else should be used!). If you push too hard the paper will crumble or fold, so be gentle. See how fast you can get each ball to move by the time it crosses the finish line. Using the paper to the push the balls limits the amount of force you are able to use.

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Like this . …or this

Questions:

i) Which ball was moving the fastest when it crossed the finish line?

ii) Which ball was moving the slowest when it crossed the finish line?

iii) Why do you think one ball was able to be move faster than the other?

Spring Pull!

Station 7

Directions: Have one person hold the end of both scales. Now pull so that the reading on one scale is halfway between the lowest and highest number on the scale. What does the other scale read? (Don’t pull too hard!)

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Questions:

i) Describe the readings on the scales.

ii) Can you pull in a way that will produce a higher reading on one scale than the other?

iii) Can you pull in a way that will produce a reading of zero on one scale but not on the other? Explain your answer.

The Big Push...

Station 8

Directions: With your lab partner, hold two bathroom scales back to back. Now push hard on the scales and observe both readings.

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Questions:

i) How do the readings compare?

ii) Can you and your partner push in a way that will produce a higher

reading on one scale than the other?

iii) Summarize your findings from stations 10 and 11.

Up Up & Away!

Station 9

Directions: Blow up the balloon and attach the hub to the blade assembly. Now release the helicopter and watch it go!

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Questions:

i) Why do you think the helicopter flies?

ii) Try holding the balloon from the bottom while the blades spin. Do the helicopter’s blades push on the surrounding air? How do you know this? Does the air surrounding the blades push on the blades? Which of these two forces causes the helicopter’s motion?

iii) Would a helicopter fly in outer space where there is no atmosphere? Why or why not?

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