Download 6.P.3A.2 Notes

Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
Performance Indicator 6.P.3A.2
Develop and use models to exemplify the conservation of energy as it is transformed from kinetic to
potential (gravitational and elastic) and vice versa.
The Law of Conservation of Energy
1. What does the Law of Conservation of Energy state? The Law of Conservation of Energy states
that energy cannot be created nor destroyed.
2. Energy can be transformed from one form into another, but the total amount of energy never
changes.
Mechanical Energy Transformations
3. What is mechanical energy? the energy due to the motion (kinetic) and position (potential)
of an object
4. Water behind a dam is an example of gravitational potential energy.
5. The gravitational potential energy of the water changes to kinetic energy in the movement of the
water as it flows over the dam.
6. When a book is lifted to a shelf, kinetic energy is transformed into potential energy. If the book
falls off the shelf the gravitational potential energy is transformed to kinetic energy.
7. When a rubber band is stretched, kinetic energy is transformed into elastic potential energy.
8. True or False. The further back you stretch the rubber band, the greater elastic potential energy,
and the more energy that will be transferred as kinetic energy.
9. What type of transformation occurs when a stretched rubber band is released? When a stretched
rubber band is released its elastic potential energy is transformed into kinetic energy as
the rubber band moves.
Energy is Conserved during Energy Transformations
10. True or False. Transformations may occur between any of the various types of energy but energy
itself is never lost.
11. The potential energy that a book on a shelf has is from the kinetic energy it took to lift the book
to the shelf.
12. A swing pendulum (such as a Newton’s cradle) also demonstrates how energy is conserved as it
changes forms.
13. Kinetic energy is used to pull a ball back; this energy is transformed into potential energy.
14. The ball is released and the ball swings back toward the other three balls (kinetic energy).
15. The moving ball strikes the stationary ball and the kinetic energy is transferred from one ball to
the next.
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
16. The last ball swings away from the others because of the kinetic energy that was transferred to
the ball.
17. If this experiment is repeated by pulling back two balls, then two balls will swing off of the other
end.
18. What causes the pendulum to eventually stop? Friction
19. Why does a swing pendulum demonstrate conservation of energy? This shows conservation of
energy because one ball has enough potential energy to cause one ball to move; two balls
cause two to moves, and so on.
20. Although energy is not lost during energy transformations, some is transformed into heat and
friction.
21. The friction transforms the energy that was originally mechanical energy in the swinging pendulum
into heat.
22. This means that all of the potential energy stored in a book is not going to be transformed into
kinetic energy.
Calculating Potential Energy and Kinetic Energy
23. Complete the table below.
Quantity SI Unit of Measurement
Force
Newton (N)
Height
Meter (m)
Work
Joule (J)
Mass
Kilogram (kg)
Energy
Joule (J)
Kinetic Energy
24. The kinetic energy of an object depends on both its speed and its mass.
25. What is the formula for calculating kinetic energy? KE = ½ x Mass x Speed2
26. Give an example. Suppose a boy is pulling a 10kg wagon at a speed of 1 m/s. KE of wagon = ½
x 10kg x (1 m/s)2 = 5kg x m2/s2 = 5J (joules)
Potential Energy
27. What is the formula for calculating potential energy? PE = Mass x Gravity X Height
28. The force of gravity is 9.8 m/s2.
29. Give an example. Find the potential energy of a body of mass 5kg and is 25m above from
the ground? 5 kg × 9.8 m/s2 × 25 m = 1225 J
30. The formula for potential energy is weight x height.
31. Give an example. A cinder block is sitting on a platform 20 m high. It weighs 79 N. 79 N x
20 m = 1590J
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
32. 1 kg x m2/s2 = 1 joule
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
Performance Indicator 6.P.3A.2
Develop and use models to exemplify the conservation of energy as it is transformed from kinetic to
potential (gravitational and elastic) and vice versa.
The Law of Conservation of Energy
1. What does the Law of Conservation of Energy state?
2. Energy can be _________________ from one form into another, but the total amount of energy
never _________________.
Mechanical Energy Transformations
3. What is mechanical energy?
4. Water behind a dam is an example of _________________ energy.
5. The gravitational potential energy of the water changes to _________________ energy in the
_________________ of the water as it flows _________________ the dam.
6. When a book is _________________ to a shelf, _________________ energy is transformed
into _________________ energy. If the book _________________ off the shelf the
_________________ energy is transformed to _________________ energy.
7. When a rubber band is _________________, _________________ energy is transformed
into _________________ potential energy.
8. True or False. The further back you stretch the rubber band, the greater elastic potential energy,
and the more energy that will be transferred as kinetic energy.
9. What type of transformation occurs when a stretched rubber band is released?
Energy is Conserved during Energy Transformations
10. True or False. Transformations may occur between any of the various types of energy but energy
itself is never lost.
11. The _________________ energy that a book on a shelf has is from the kinetic energy it took
to lift the book to the shelf.
12. A swing _________________ (such as a Newton’s cradle) also demonstrates how energy is
conserved as it changes forms.
13. Kinetic energy is used to _________________ a ball back; this energy is transformed into
_________________ energy.
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
14. The ball is _________________ and the ball swings back toward the other three balls
(_________________ energy).
15. The moving ball _________________ the stationary ball and the kinetic energy is
_________________ from one ball to the next.
16. The _________________ ball swings away from the others because of the
_________________ energy that was transferred to the ball.
17. If this experiment is repeated by pulling back two balls, then _________________ balls will
swing off of the other end.
18. What causes the pendulum to eventually stop?
19. Why does a swing pendulum demonstrate conservation of energy?
20. Although energy is not lost during energy transformations, some is transformed into
_________________ and _________________.
21. The friction transforms the energy that was originally mechanical energy in the swinging pendulum
into _________________.
22. This means that _________________ of the potential energy stored in a book is
_________________ going to be _________________ into kinetic energy.
Calculating Potential Energy and Kinetic Energy
23. Complete the table below.
Quantity SI Unit of Measurement
Force
Newton (N)
Height
Work
Joule (J)
Mass
Energy
Kinetic Energy
24. The kinetic energy of an object depends on both its _________________ and its
_________________.
25. What is the formula for calculating kinetic energy?
26. Give an example. Suppose a boy is pulling a 10kg wagon at a speed of 1 m/s.
Potential Energy
27. What is the formula for calculating gravitational potential energy?
28. The force of gravity is _________________.
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016
29. Give an example. Find the potential energy of a body of mass 5kg and is 25m above from the
ground?
30. The formula for potential energy is ______________________.
31. Give an example. A cinder block is sitting on a platform 20 m high. It weighs 79 N.
32. 1 kg x m2/s2 = _____________________.
Energy Transfer and Conversation Study Guide 2 of 8 (8/22 – 10/10)
Name ______________________________________________ Date __________________ Unit Test on 10/12/2016