MECHANICAL ENERGY PHYSICS 9 summative test

Science 9

1. Name: _________________________________ Grade & section: ___________________
CONSERVATION OF MECHANICAL ENERGY
I.Identify whether the following has Potential or Kinetic Energy. Write the number in each
corresponding column. If the activity is classified as potential energy, indicate the specific
type of potential energy.
POTENTIAL ENERGY KINETIC ENERGY
II. Classify whether the description pertains to Potential Energy (PE) or Kinetic Energy
(KE). Write PE or KE in the space provided.
__________1. Energy possessed by a moving tricycle.
__________2. An energy of motion, observable as the movement of an object, particle, or set of
particles.
__________3. Energy due to the position of an object
__________4. Energy waiting to be used
III.Write TRUE if the statement is correct and if FALSE change the underlined word
to make the statement correct.
________1. The total mechanical energy of a given system is changeable.
________2. Conservation of mechanical energy refers to the total sum of the potential energy
and kinetic energy of a system that remains the same as long as the only forces acting are
conservative forces.
________3. In the law of conservation of energy, the decrease in potential energy is the same as
the increase in kinetic energy.
________4. A thrown baseball has kinetic energy.
________5. Potential energy is energy of motion.
________6. The faster an object moves, the smaller kinetic energy it has.
________7. When you are holding a book, energy is stored between the book and Earth; this
type of energy is called potential energy.
________8. Mechanical energy is the total amount of potential energy and total amount of
kinetic energy.
________9. The wind blowing through your hair is an example of potential energy.
_______10.The “Law of Conservation of Mechanical Energy” states that the total mechanical
energy in a system remains constant as long as the only forces acting are conservative forces.
IV. Choose the letter of the correct answer and write it in the separate sheet of paper.
____ 1. What does the law of conservation of mechanical energy state?
A. Potential energy is always equal to kinetic energy
B. Potential energy is always converted to kinetic energy
C. There is always some energy lost as heat
D. For any system the total amount of mechanical energy remains the same
____ 2. Why would a system have less energy than it originally started with?
A. The energy was lost as heat.
B. The energy was destroyed.
C. More energy was created at the beginning than at the end.
D. The temperature was too low to create heat.
____ 3. Which best describes potential energy?
A. Energy of motion B. Energy as heat
C. Stored energy D. Energy that is doing work
____ 4. Which of the following happens to the energy of a coconut that falls freely?
A. Loses potential and gains kinetic energy.
B. Loses both potential and gains kinetic energy.
C. Gains potential and loses kinetic energy.
D. Gains both potential and kinetic energy.
____ 5. The wind-up toy that is fully wound and at rest possesses
A. kinetic but no potential energy B. potential but no kinetic
C. both potential and kinetic energy in equal amountsD. neither PE nor KE
1. A mango fruit high up in a tree 6. A jeepney traveling down the road
2. A ball rolling down a hill 7. A paper airplane flying through the air
3. A large stick of dynamite 8. An asteroid falling towards the earth
4. A stretched rubber band 9. Standing on the stage
5. A set of double “A” batteries in a remote 10. A book on top of a table
control

2. Name: _________________________________ Grade & section: ___________________
LAW OF CONSERVATION OF MECHANICAL ENERGY
I.Since the Total mechanical energy is the sum of the Potential and kinetic energy, complete
the table by finding the Total mechanical energy.
No PE
(J)
KE
(J)
MET = PE + KE
(J)
1 200 100 ___________
2 400 ___________ 500
3 25 20 ___________
4 0 75 ___________
5 40.5 59.5 __________
6 _________ 36.75 100
7 75 ___________ 100
8 50 50 ___________
9 375 ___________ 375
II.Direction: Modified True or False: Write True if the statement is correct. If the statement is
False, change the underlined word or group of words to make the whole statement true.
__________ 1. Objects that have kinetic energy are not moving.
__________ 2. Potential energy is dependent upon the height or position of the object.
__________ 3. The product of potential energy and kinetic energy is called total
mechanical energy.
__________ 4. The energy due to the change of height or position of the object is
Kinetic energy.
__________ 5. The formula for Total Mechanical Energy is MET = PE + KE.
__________ 6. The SI unit of energy is joule.
__________ 7. Potential energy depends on the height or distance and mass of the
object.
__________ 8. When you hit the hammer on the table, the stored potential energy in
the hammer is converted to kinetic energy as the hammer moves
down.
__________ 9. The difference between mechanical and kinetic is their ability to
transform into each other.
__________10. When the book hits the floor, this energy of motion will again convert
to kinetic energy.
III.LET ME TAKE A RIDE
A.ANALYSIS: Juan is riding a cart moving up on a frictionless ramp from points A to C.
What happens to the Kinetic, Potential and Total Mechanical energy in every point?
Given the figure above, complete the data in the table.
POINT KE (J) PE (J) ME (J)
A 0 15
B 7
C 15
1. At which point/s is potential energy maximum?
___________________________________________________________________________
2. What happens to the total mechanical energy as the cart moves from A to C?
___________________________________________________________________________
3. What happens to the potential energy and kinetic energy as the cart moves from
A to C?
_____________________________________________________________________________
B.FIXING POINT
POINT PE
(J)
KE
(J)
MET = PE + KE
(J)
A 50 000 J 0 J
B 40 000 J 50 000 J
C 30 000 J
D 0 J