PHYSICS 165 MODULE 4 EXAM
QUESTIONS AND ANSWERS (GRADED A)
/. What is the process of producing change in the environment called? - Answer-✅Work
/.What is the unit for both energy and work? - Answer-✅Joules
/.Which of the following changes will decrease the amount of work done by a force -
Answer-✅a) Make the force as large as possible
b) Increase the angle between the force and the displacement
c) Apply the force over a larger displacement
d) Apply the force in the same direction as the displacement
Answer: B
/.How can a waiter apply a force to a tray and NOT do any work on it? - Answer-
✅Either apply the force in a direction that is perpendicular to the displacement, have no
displacement
/.When the energy of a system increases, what type of work is most likely done ON that
system? - Answer-✅a) positive work
b) negative work
c) zero work
d) there is no relationship between work and energy
Answer: A
/.Which two of the follow will affect the amount of work you do in lifting a book onto a
shelf? - Answer-✅a) the path that the book takes as you lift it to the shelf
b) the time it takes you to lift it to the shelf
c) the height of the shelf
d) the mass of the book
Answer C and D
/.Which of the following forces is an example of a non-conservative force? - Answer-
✅a) Electric
b) Friction
c) Gravity
, d) Magnetic
Answer: B
/.True or False: A football is kicked into the air. As it rises, its kinetic energy decreases
and its gravitational potential energy increases. - Answer-✅True
/.If you wanted to make the kinetic energy of a thrown ball larger, what two things could
you do to make the kinetic energy of the ball FOUR times bigger? - Answer-✅Double
the speed and make the mass 4x bigger
/.Of the following choices, which TWO of them will decrease the gravitational potential
energy of an object? - Answer-✅a) Increase the mass of the object
b) Decrease the mass of the object
c) Increase the height of the object above the reference frame
d) Decrease the height of the object above the reference frame
Answer B and D
/.What is the definition of power? - Answer-✅Power = W/T
The rate of doing work or the rate of energy transfer
/.Which TWO of the following choices are units for power? - Answer-✅a) Amperes
b) Horsepower
c) Joules
d) Watts
Answer: B and D
/.During a workout, an athlete pulls a pile bricks horizontally with a force of 475.0 N
across the floor that is 20.0 m long. Answer the following questions about this scenario:
a. Calculate the amount of work done on the pile of bricks by the athlete.
b. What equation can be used to calculate the work done by the athlete on the pile of
bricks?
c. If the athlete completes another rep but this time applies the same 475.0 N force an
angle of 25.0∘above horizontal, how much work does she do now?
d. Calculate how much work gravity does on the pile of bricks if the mass of the bricks is
105 kg.
e. If the athlete moves the bricks at a constant speed during all of the reps, what is the
net work done on the bricks during any of these trials? - Answer-✅a) W=Fdeltadcos()
answer in J
b) 2
c) W=Fdcos()
Answer in J
QUESTIONS AND ANSWERS (GRADED A)
/. What is the process of producing change in the environment called? - Answer-✅Work
/.What is the unit for both energy and work? - Answer-✅Joules
/.Which of the following changes will decrease the amount of work done by a force -
Answer-✅a) Make the force as large as possible
b) Increase the angle between the force and the displacement
c) Apply the force over a larger displacement
d) Apply the force in the same direction as the displacement
Answer: B
/.How can a waiter apply a force to a tray and NOT do any work on it? - Answer-
✅Either apply the force in a direction that is perpendicular to the displacement, have no
displacement
/.When the energy of a system increases, what type of work is most likely done ON that
system? - Answer-✅a) positive work
b) negative work
c) zero work
d) there is no relationship between work and energy
Answer: A
/.Which two of the follow will affect the amount of work you do in lifting a book onto a
shelf? - Answer-✅a) the path that the book takes as you lift it to the shelf
b) the time it takes you to lift it to the shelf
c) the height of the shelf
d) the mass of the book
Answer C and D
/.Which of the following forces is an example of a non-conservative force? - Answer-
✅a) Electric
b) Friction
c) Gravity
, d) Magnetic
Answer: B
/.True or False: A football is kicked into the air. As it rises, its kinetic energy decreases
and its gravitational potential energy increases. - Answer-✅True
/.If you wanted to make the kinetic energy of a thrown ball larger, what two things could
you do to make the kinetic energy of the ball FOUR times bigger? - Answer-✅Double
the speed and make the mass 4x bigger
/.Of the following choices, which TWO of them will decrease the gravitational potential
energy of an object? - Answer-✅a) Increase the mass of the object
b) Decrease the mass of the object
c) Increase the height of the object above the reference frame
d) Decrease the height of the object above the reference frame
Answer B and D
/.What is the definition of power? - Answer-✅Power = W/T
The rate of doing work or the rate of energy transfer
/.Which TWO of the following choices are units for power? - Answer-✅a) Amperes
b) Horsepower
c) Joules
d) Watts
Answer: B and D
/.During a workout, an athlete pulls a pile bricks horizontally with a force of 475.0 N
across the floor that is 20.0 m long. Answer the following questions about this scenario:
a. Calculate the amount of work done on the pile of bricks by the athlete.
b. What equation can be used to calculate the work done by the athlete on the pile of
bricks?
c. If the athlete completes another rep but this time applies the same 475.0 N force an
angle of 25.0∘above horizontal, how much work does she do now?
d. Calculate how much work gravity does on the pile of bricks if the mass of the bricks is
105 kg.
e. If the athlete moves the bricks at a constant speed during all of the reps, what is the
net work done on the bricks during any of these trials? - Answer-✅a) W=Fdeltadcos()
answer in J
b) 2
c) W=Fdcos()
Answer in J
