Conservation of Mechanical Energy Activity

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Conservation of Mechanical Energy Activity

Materials: three balls of different masses, a ruler or meter stick

Objectives: To calculate the potential and kinetic energies of a ball dropped from rest from some initial height thereby demonstrating the conservation of mechanical energy.

Equations: [pic] becomes [pic]

Initially all of the energy is ___________________ , and right before the ball hits the table/ground all of the (final) energy is ____________________.

Equation for initial mechanical energy: _______________________

Equation for final mechanical energy: ______________________

Equation for final velocity: ____________________

Directions: Show all calculations and explain all answers. Follow the steps below.

1. Drop each of the three balls from three different heights of your choice. Perform three trials for each height. Note how each ball bounces upon impact.

2. Record the heights in the table below. Use the equations above to calculate the potential and kinetic energies as well as the final velocity. The masses are: #1 Plastic ball: 0.0045 kg, #2 Metal ball: 0.0048 kg, and #3 Rubber ball: 0.01 kg

|Mass of Ball |Initial Height |Initial Mechanical Energy |Final Mechanical |Final Velocity (m/s) |

|(kg) |(m) |(J) |Energy (J) | |

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Conservation of Mechanical Energy Activity

Questions:

1. Which ball bounced the highest and which ball bounced the lowest? Try to explain why they bounced this way?

2. Is there a relationship between energy and how the balls bounced? Explain.

3. Is there a relationship between initial mechanical energy and height? Explain.

4. Is there a relationship between final mechanical energy and final velocity? Explain.

5. Show a sample calculation from your data table for the initial mechanical energy and the final velocity for one trial of one of the balls.

6. Is energy conserved after the ball hits the table/ground and bounces or rolls? Explain why or why not.

7. If the balls experienced air resistance during their fall, would energy be conserved? Explain why or why not.

8. Which ball/trial had the most initial mechanical energy? Which ball/trial had the most final mechanical energy? Does this make sense in terms of conservation of mechanical energy?

9. Which ball/trial had the lowest initial mechanical energy? Which ball/trial had the lowest final mechanical energy? Does this make sense in terms of conservation of mechanical energy?

10. As the ball falls what happens to the energy?

Conservation of Mechanical Energy Activity

Questions:

1. Which ball bounced the highest and which ball bounced the lowest? Try to explain why they bounced this way?

2. Is there a relationship between energy and how the balls bounced? Explain.

3. Is there a relationship between initial mechanical energy and height? Explain.

4. Is there a relationship between final mechanical energy and final velocity? Explain.

5. Show a sample calculation from your data table for the initial mechanical energy and the final velocity for one trial of one of the balls.

6. Is energy conserved after the ball hits the table/ground and bounces or rolls? Explain why or why not.

7. If the balls experienced air resistance during their fall, would energy be conserved? Explain why or why not.

8. Which ball/trial had the most initial mechanical energy? Which ball/trial had the most final mechanical energy? Does this make sense in terms of conservation of mechanical energy?

9. Which ball/trial had the lowest initial mechanical energy? Which ball/trial had the lowest final mechanical energy? Does this make sense in terms of conservation of mechanical energy?

10. As the ball falls what happens to the energy?

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