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-228600-2286001001Calculating Speed You have encountered speed when you were in a car. The speedometer read 25 miles per hour (mph). This is how speed is written. The speed is the distance an object moves in a certain period of time. So, to have a speed you must have a distance (in this case miles) and a time (hour). In science we typically use the metric system for the distances, either meters or kilometers, and we use seconds for the time. The abbreviation we use in science is usually m/s – meters per second. Now we will learn to calculate the speed of a toy car along a 50-centimeter racetrack.Activity 1Materials: toy car, 4 books the same height, board for a ramp, masking tape, meter stick, timer, calculatorWhat To Do:1. Place two books on the floor then place the board at the edge of the book.2. Place a piece of masking tape at the end of the ramp for the Start Line. 3. Measure 50 cm from the end of the ramp on the floor and place another piece of masking tape there as the Finish Line. 4. Place the car at the top of the ramp. (See picture below)2286005715Bookcarramp Start 50 cm Finish00Bookcarramp Start 50 cm Finish5. Set your timer at zero and let the car go down the ramp.3200400-37719000Name _______________period _____-331470-504825210021EXIT TICKET1. On a speed and time graph a line going down meansA. The object is speeding up.B. The object is slowing down.C. The object is stopped.D. The object is traveling at a constant speed.2. On a speed and time graph a flat line meansA. The object is speeding up.B. The object is slowing down.C. The object is stopped.D. The object is traveling at a constant speed.3. On a speed and time graph a flat line meansA. The forces are unbalanced.B. The forces are balanced.Conclusion: (balanced, slope, speeding up, constant, unbalanced)When graphing motion we look at the _________ of the line. A steep slope going up means an object is ___________ ______. If the line is flat it means the object is moving at a _________ speed. When an object is moving at a constant speed the forces are ________. When an object is speeding up then the forces are ____________.3886200-22860020026. Start the timer when the car gets to the Start Line and stop the timer when it gets to the Finish line. Record the seconds in the data table below.7. Repeat 2 more times and record the seconds below.8. Add another book and repeat the 3 time trials.9. Add the fourth book and repeat the 3 time trials.10. Use the calculator to find the total and the average time. Number of BooksTrial 1Trial 2Trial 3TotalAverage234Questions:1. What was the distance the car traveled each time? ____2. What were the average times? ______ ______ _____3. Why did we find the average? _____________________To calculate speed we must divide the distance by the time. Use the data from the data table to determine the speed of your car. Don’t forget the units.Speed = distance traveled timeSpeed for 2 books = ___ cm ____ seconds = ____Speed for 3 books = ___ cm ____ seconds = ____Speed for 4 books = ___ cm ____ seconds = ____4. What unit did you use for speed? ________________5. Which number of books gave the car the greatest speed? ____________6. Why do you think this might be true? ____________-281940-1739903003Find the following speeds. Don’t forget your units.a. A toy train went around a 6m track in 3 minutes. _______b. A student ran the 200m track in 2 minutes. ___________c. An airplane flew for 500 km in 20 minutes. ___________d. A car traveled for 10 km in 5 minutes. ______________e. A school bus traveled 100 km in 2 hours. ____________Define the following terms using your text book pgs. 388-397.Position:_____________________________________________________________________________________________Reference Point:______________________________________________________________________________________Motion:_____________________________________________________________________________________________Force:_______________________________________________________________________________________________Speed:______________________________________________________________________________________________Velocity:____________________________________________________________________________________________4090035-218440200020When you are traveling in a car that is speeding up you can feel the force pushing back into the seat. This is an unbalanced force. When you are slowing down you can feel the force pushing you away from the seat. This, too, is an unbalanced force. But when you are traveling down the freeway at a constant speed you cannot feel a force pushing on you. This is a balanced force.91440020320Speed m/sTime (sec)Traveling Train00Speed m/sTime (sec)Traveling TrainLook at the graph above and answer the following questions.1. In which segments of the line is the train speeding up?___________________________________________2. In which segments of the line is the train traveling at a constant speed? _____________________________3. In which segments are the forces unbalanced? _______4. In which segments are the forces balanced? _________-29419812065190019When you look at a line on a graph you can talk about its slope. It can be steep (like trying to go up or down a mountain) or it can be flat.If it has a steep slope going up that means the car is speeding up (acceleration).If it has steep slope going down that means the car is slowing down (acceleration).If the line is flat that means the cars is traveling at a constant speed.Questions:1. Between what times is your car speeding up? _________2. How do you know this? __________________________3. Between what times is your car slowing down? _______4. How do you know this? __________________________5. Between what times is your car traveling at a constant speed? _______________________________6. How do you know this? __________________________When you learned how to calculate net forces you found that the objects moved to the left or right if the forces were not equal. We call these forces that cause movement unbalanced forces.You also found that some objects had equal forces and did not move. These are called balanced forces.4259580-22415540043657600-28130500Name _____________period _____EXIT TICKETCalculate the following speeds. Don’t forget your units!1. A skateboard went around a 10m track in 2 minutes. 2. A motorcycle sped down the 500m track in 2 minutes. 3. A rocket flew 1000 km in 2 minutes. Conclusion: (seconds, distance, minutes, time, faster, kilometers, meters, greater)Speed can be calculated by dividing the ___________ by the ___________. In science, distances can be measured in __________ or ___________ . For time we usually use ________ but can also use _________. We found during this lab that the ___________ the height the ___________ the speed.-114300-1714505005Graphing MotionAn object is in motion when its distance from another object is changing. When you are traveling in a car, you are in motion along with the car. You can show the motion of an object on a line graph in which you plot distance against time. On a distance-time graph, place time on the horizontal axis and distance on the vertical axis. Label each axis as time or distance with the appropriate unit of measurement in parentheses. Example: Distance (cm) or Time (s).Materials: Sidewalk outside marked in 5-meter increments up to 25 meters, 5 timersWhat To Do:1. Have one student with a timer at the 5, 10, 15, 20 and 25 meter marks.2. Have one student volunteer to walk from the starting line to the 25 meter line.3. Have each student with a timer start their timer when the student starts walking and stop when the walking student passes them.4. Record the time in the data table below.5. Make a line graph of your data. Be sure to place the time on the X-axis and distance on the Y-axis. Don’t forget your title.Time (s)Distance (m)5101520254177665-228600180018Graphing Changes in MotionWe have learned how to calculate the speed of toys cars. We have also learned how to graph constant speed. The graph of an object traveling at a constant speed is a straight line. The graph of an object traveling at a changing speed (acceleration) is a segmented line. Now we will learn how to graph the changes in speed. Materials: noneWhat To Do:1. Use the following information to make a motion graph of a car traveling down the street.2. Don’t forget a title, labels and units.Time in sec.Speed in m/s00102520303040404050506030-348615-2260601700174566285-22606000Name _______________period ____EXIT TICKETBalanced and Unbalanced Forces1. The net force acting on the box is – 2762250222253 N003 N20040609398000a. 0 Nb. 6 Nc. 10 N2. The forces acting on this box are –a. balanced27622501860553 N003 Nb. unbalancedc. nonNewtonian3. What will happen to the box?a. It will move to the right.b. It will move upwards.c. It will not change its motion4. The net force on the box to the right is 900 N. The down force is 200 N. How much force is acting in the direction of C?a. 200 Nb. 700 Nc. 1100 N5. The forces acting on the box are-a. balancedb. unbalancedc. nonNewtonian4171950-22606060064260850-22606000-232600515176500-232600524828500Since the relationship between distance and time is known as speed, you can easily calculate the average speed of an object from a distance-time graph. Speed = distance / timeQuestions:1. Find the speed of the student at 10 meters. ________________2. Find the speed of the student at 20 meters.________________3. Find the speed of the student at 25 meters.________________ 4. Find the average speed of the student.-298450-1117607007Sometimes two objects are moving side-by-side but at different speeds. You can graph this information on a double line graph. Look at the table below of the distance crawled by two babies.Materials: 2 different colored pencilsWhat To Do:1. Make a double line graph of the following information. Be sure to color in the key.Time in secondsBaby SarahDistance (m)Baby ScottDistance (m)00051110231534204625573429000283210 Baby Sarah Baby Scott00 Baby Sarah Baby ScottQuestions:1. What is the average speed of Sarah? _____________2. What is the average speed of Scott? _____________3. Which baby is traveling the fastest? _____________4. Look at the two different lines. How can you tell by looking at the graph which baby has the fastest speed?_____________________________________________4051935-111760160016Materials: Net Forces CardsWhat To Do:1. Look at the cards you and your partner have been given.2. Place the 5 “word” cards on your table.3. Look at the “force” cards and place them in the correct categories found on the word cards.Questions:1. Which “force” cards belong in the category Moves Up? ________________________________2. Which “force” cards belong in the category Moves Down? ______________________________3. Which “force” cards belong in the category Moves Left? _______________________________4. Which “force” cards belong in the categoryMoves Right? ______________________________5. Which “force” cards belong in the categoryStays Still? ________________________________6. Calculate the net force on card A. ______________7. Are the forces balanced or unbalanced? _________8. Does the object move or stay still? _____________9. Calculate the net force on card C. ______________10. Are the forces balanced or unbalanced? _______11. Does the object move or stay still? _____________12. Calculate the net force on card M. _____________13. Are the forces balanced or unbalanced? _________14. Does the object move or stay still? _____________15. What happens to objects with unbalanced forces?____________________________________________-348615-111760150015Net ForcesTo find the net force when forces are acting in the same direction, simply add them together.56578517907000To find the net force when forces are acting in opposite directions, simply subtract the small force from the larger force.When the net force is zero, the forces are balanced. Balanced forces do not cause a change in an object’s motion.4193540-11176080083429000-28575000Name _______________period _____EXIT TICKETLook at the graph below.2128520298451. Which train is moving fastest? ____2. How do you know?___________________3. Which train is moving slowest? _____4. How do you know?___________________5. What is Train A’sspeed? ____________Conclusion: (y-axis, distance, dividing, motion, changing, x-axis, time)An object is in ________ when its distance from another object is _________. You can graph motion if you know the __________ and the time. The distance is placed on the ______ and the time is placed on the __________. Speed is calculated by ________ distance by the ________.-234315-952509009Force and MotionWhen you ride a bike, your foot pushes against the pedal. The push makes the wheels of the bike move. When you drop something, it is pulled to the ground by the force of gravity. In science a force is defined as a push or a pull. Forces affect how objects move. The simplest forces are pushes and pulls. A force can put an object into motion, or it can slow the object down, speed it up or change the direction of an object that is already moving. At other times, a force can have no effect at all. In this case, the force may be canceling out the effect of another force (balanced forces).The size of a force can be measured using a spring scale and is recorded in the unit of Newtons (N). The abbreviation is written with a capital letter because it is named after Sir Isaac Newton.Watch your teacher complete a demonstration. Answer the following questions.1. Which ramp placed a greater impact of force on the car? Explain.2. Which mass had a greater impact of force on the car? Explain.4051935-168910140014 Look at the picture below and answer the questions.Questions:1. How many people are pulling on the right side? _____2. How many people are pulling on the left side? ______3. Compare the arrows in the picture. _____________________________________________________________4. What is the force in the arrow to the right? __________5. What is the force in the arrow to the left? ___________6. Are the forces balanced or unbalanced? ____________7. What direction is the rope moving? _______________-234315-111760130013Balanced and Unbalanced ForcesWe have learned that arrows can represent forces. Did you notice that the bigger the arrow, the larger the force? If the arrows are the same size, then the forces are equal.A force has both size and direction. Usually more than one force acts on an object at the same time. Forces may work together or they may be opposite forces. Two or more opposite forces are balanced if they are equal and do not cause a change in the object’s motion. If one force is stronger than the other the forces are unbalanced forces. Unbalanced forces can cause a change in motion, speed and/or direction. The net force is the combination of all forces acting on an object.Look at the picture below and answer the questions.-23431580010Questions:1. How many people are pulling on each side? _____2. Compare the size of the arrows in the picture._________________________________________3. What is the force in each arrow? ___________4. Are the forces balanced or unbalanced? _________5. Which direction do you expect the rope to move? _____6. What would have to change for the rope to move? ___________________________________________4124960-2063751000103225800156210Activity 1: Using the Spring ScaleWhat To Do:1. Observe the diagram of the spring scale.2. Notice on one side it measures grams and on the other side it measures Newtons.3. What relationship do you observe between grams and Newtons?____________________________4. Observe the Newton side of the spring scale. With your teacher determine what each line between the numbers represents. _________________5. Use a colored pencil and mark the following amounts on the diagram above. 0.6 N1.4 N2.8 N4.6 NActivity 2 Measuring ForcesMaterials: spring scale, agenda, 100g, 200g, or 500g hooked mass, scissors What To Do:1. Observe the spring scale. Make sure you know how to read them.2. Hook your spring scale into the binding around your agenda and pick it up.3. Read the scale. Record your observation below.4. Repeat with the hooked mass and scissors.5. Don’t forget your units!-358140-152400110011-5332095-6899910150015Object Size of Force (N)AgendaHooked massScissorsQuestions:1. Which object required the greatest amount of force to lift? ___________________________2. Which object required the least amount of force to lift? ____________________Forces We can show forces by using arrows (they are easy to draw and give lots of information about the force).Look below at some examples.Here is a ball. There are 2 forces acting on the ball. 1. Look at the arrows and determine if the ball is moving or still.______________________ 2. If you think it is moving, in which direction would you say it is moving?___________________________3. If you wanted to show that the ball was still, what do you think the arrows would look like? Draw the ball and two arrows below.4210050-223520120012 Name _______________period ____EXIT TICKETForce and Motion1. In what unit do we measure force?a. metersb. litersc. Newtons2. What type of equipment is used to measure force?a. spring scaleb. balancec. graduated cylinder3. What can you tell about the forces from the arrows below?a. The forces are equalb. The force on the left is largerc. The force on the right is larger4. In which direction is the car moving in the picture below?362864541000a. to the rightb. to the leftc. it is not moving ................
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