PHYS 165 Module 4 Exam Questions with Correct Answers
What is the process of producing change in the environment called?
Energy
Work
Force
Power - Answers Work
"Johnny, it is time to go to work." Which meaning of the word work does this sentence use?
The everyday meaning of work
The scientific meaning of work - Answers The everyday meaning of work
"Mowing the grass is hard work." Which meaning of the word work does this sentence use?
The everyday meaning of work
The scientific meaning of work - Answers The scientific meaning of work
What is the unit of both energy and work?
Newtons
Kilograms
Watts
Joules - Answers Joules
A) Give an example of a situation where a force is applied to an object and it moves, but the
force does no work on the object.
B) Explain why the force does no work on the object. - Answers An example is closing a sliding
glass door. Gravity does no work on the door since the force and the displacement are
perpendicular to each other
A) Describe a situation where a force is exerted on an object for a large amount of time but that
force does no work.
B) Explain why that force does no work. - Answers An example is a dump truck parked in a lot.
There is a large amount of gravitational force, as well as a large normal force, but there is no
displacement, so no work has been done.
A) Under what conditions does the rope cause the car to increase in energy?
, B) Under what conditions does the rope cause the car to decrease in energy? - Answers if the
rope pulls in the same direction of the displacement, the energy will increase, whereas if the
rope pulls in the opposite direction, the energy will decrease
A) Does the work you do on a book as you lift it onto a shelf depend on the path that the book
takes?
B) On the time it takes?
C) On the height of the shelf?
D) On the mass of the book? - Answers A) No
B) No
C) yes
D) yes
Give an example of a conservative force. - Answers gravity, electricity, magnetism, and elasticity.
Describe the energy transformations in the throwing of a football. Start with the quarterback
picking up the football, throwing it downfield, and end with the football landing incomplete on
the ground. - Answers The football starts with no energy. When the quarterback picks up the
football, he does work on the football, thereby increasing both the kinetic energy and the
gravitational potential energy. During the throw, the kinetic energy of the football is greatly
increased. Once it lets go, the football goes up and increases in gravitational potential energy
and decreases in kinetic energy until it reaches the top of the path. As it starts to come down,
the gravitational potential energy decreases, and the kinetic energy increases. Once it hits the
ground, the gravitational potential energy has all been converted to kinetic energy. Friction and
heat then take the kinetic energy away from the football as it rolls to a stop.
A) Explain why it is easier to climb a mountain in a zigzag path rather than one that is straight
up the mountain.
B) Compare the amount of increase in your gravitational potential energy in each case. -
Answers A) It is easier along a zigzag path because the force needed is less. This is because
the work is being done over a larger distance. B) The amount of gravitational potential energy is
the same in both cases.
What is the rate of doing work called?
Energy
Work
Force
What is the process of producing change in the environment called?
Energy
Work
Force
Power - Answers Work
"Johnny, it is time to go to work." Which meaning of the word work does this sentence use?
The everyday meaning of work
The scientific meaning of work - Answers The everyday meaning of work
"Mowing the grass is hard work." Which meaning of the word work does this sentence use?
The everyday meaning of work
The scientific meaning of work - Answers The scientific meaning of work
What is the unit of both energy and work?
Newtons
Kilograms
Watts
Joules - Answers Joules
A) Give an example of a situation where a force is applied to an object and it moves, but the
force does no work on the object.
B) Explain why the force does no work on the object. - Answers An example is closing a sliding
glass door. Gravity does no work on the door since the force and the displacement are
perpendicular to each other
A) Describe a situation where a force is exerted on an object for a large amount of time but that
force does no work.
B) Explain why that force does no work. - Answers An example is a dump truck parked in a lot.
There is a large amount of gravitational force, as well as a large normal force, but there is no
displacement, so no work has been done.
A) Under what conditions does the rope cause the car to increase in energy?
, B) Under what conditions does the rope cause the car to decrease in energy? - Answers if the
rope pulls in the same direction of the displacement, the energy will increase, whereas if the
rope pulls in the opposite direction, the energy will decrease
A) Does the work you do on a book as you lift it onto a shelf depend on the path that the book
takes?
B) On the time it takes?
C) On the height of the shelf?
D) On the mass of the book? - Answers A) No
B) No
C) yes
D) yes
Give an example of a conservative force. - Answers gravity, electricity, magnetism, and elasticity.
Describe the energy transformations in the throwing of a football. Start with the quarterback
picking up the football, throwing it downfield, and end with the football landing incomplete on
the ground. - Answers The football starts with no energy. When the quarterback picks up the
football, he does work on the football, thereby increasing both the kinetic energy and the
gravitational potential energy. During the throw, the kinetic energy of the football is greatly
increased. Once it lets go, the football goes up and increases in gravitational potential energy
and decreases in kinetic energy until it reaches the top of the path. As it starts to come down,
the gravitational potential energy decreases, and the kinetic energy increases. Once it hits the
ground, the gravitational potential energy has all been converted to kinetic energy. Friction and
heat then take the kinetic energy away from the football as it rolls to a stop.
A) Explain why it is easier to climb a mountain in a zigzag path rather than one that is straight
up the mountain.
B) Compare the amount of increase in your gravitational potential energy in each case. -
Answers A) It is easier along a zigzag path because the force needed is less. This is because
the work is being done over a larger distance. B) The amount of gravitational potential energy is
the same in both cases.
What is the rate of doing work called?
Energy
Work
Force
