Kinetic & Potential Energy Lab



Lab: Mechanical Energy

Purpose:

• How does the release height affect the gravitational and kinetic energy of a ball?

Materials: marble, golf ball, triple beam balance, ramp, several books, stopwatch, meter stick

Introduction:

Average Velocity is the distance an object travels, in a given direction, divided by the time.

average velocity = distance / time

Potential Energy is the mechanical energy of position. In other words, potential energy is how much potential something has to do work. The formula used to measure P.E. is:

P.E. = mass x acceleration due to gravity x height = mgh

Kinetic Energy is the mechanical energy of motion. In other words, kinetic energy is how much work an object is currently doing. The formula for determining K.E. is:

K.E. = ½ x mass x velocity2 = ½ mv2

1. Measure the mass of each type of ball to the nearest 0.1 gram and record it in a data table similar to sample data table 1.

2. Convert the mass to kilograms and record.

3. You will roll the objects down a ramp to determine the average velocity, the P.E. and the K.E. for each situation. Set up a data table for each ball similar to sample data table 2.

4. Set up the ramp using 4 large books. Use a meter stick to determine the length and height of the ramp to the nearest 0.01 meters and record it in the data table.

5. Determine how long it takes each ball to roll down the ramp. Do this by placing the ball at the top of the ramp. Start the timer when you release the ball. Stop timing when the ball reaches the bottom of the ramp. Record the time it took the ball to reach the bottom of the ramp. Repeat for two more trials. Measure first one ball, then the other.

6. Repeat the procedure, varying the height of the ramp using 3 books, 2 books and 1 book. Record your results.

7. Determine the average time for each trial and record.

8. Use the average time and the length of the ramp to find the average velocity of the ball for each height. Record your results.

9. Use the mass of the ball, the acceleration due to gravity and the height of the ramp to determine the potential energy of the balls for each height.

10. Use the mass of the ball and the average velocity to determine the kinetic energy of the ball for each height.

Sample Data Table 1:

[pic]

Sample Data Table 2:

MARBLE

[pic]

11. Construct a line graph for the marble and golf ball in the space provided. This graph should contain four lines with a color-coded key, similar to the example shown. Don’t forget to label the x-axis and y-axis with an appropriate scale and give the graph a descriptive title.

Sample Graph

[pic]

Questions:

1. When was the potential energy the highest in this experiment and why?

2. When was the kinetic energy the highest in this experiment and why?

3. In theory, the potential energy at the top of the drop should match the kinetic energy at the bottom of the drop for each trial. Did all of the potential energy transfer to kinetic energy in your test? Does this mean you lost/gained any energy? Explain using the law of conservation of energy.

4. Which do you think has a greater effect on the kinetic energy of an object…mass or velocity? Why?

5. Sketch a graph similar to the one below that shows how the energy transfers from potential to kinetic energy as a ball falls from the top of a building. Draw and label three lines (one for kinetic, one for potential, and one for total mechanical energy).

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download