PHY 121 FINAL EXAM REVIEW QUESTIONS AND ANSWERS RATED
A+ 2025/2026
An object is hanging by a string from the ceiling of an elevator.
The elevator is slowing down while moving upward. What is the
magnitude of the tension in the string?
A) The tension in the string is zero.
B) The magnitude of the tension in the string is less than the
magnitude of the weight of the object.
C) The magnitude of the tension in the string is greater than the
magnitude of the weight of the object.
D) The magnitude of the tension in the string is equal to the
magnitude of the weight of the object.
E) The tension in the string cannot be determined without
knowing the speed of the elevator.
B) The magnitude of the tension in the string is less than the
magnitude of the weight of the object.
Two objects have masses m and 5m, respectively. They both are
placed side by side on a frictionless inclined plane and allowed to
slide down from rest.
A) It takes the heavier object 5 times longer to reach the bottom
of the incline than the lighter object.
B) It takes the lighter object 10 times longer to reach the bottom
of the incline than the heavier object.
C) It takes the heavier object 10 times longer to reach the bottom
of the incline than the lighter object.
D) It takes the lighter object 5 times longer to reach the bottom
of the incline than the heavier object.
,E) The two objects reach the bottom of the incline at the same
time.
E) The two objects reach the bottom of the incline at the same
time.
A packing crate is sitting at rest on an inclined loading ramp.
How does the magnitude of the force of static friction compare to
the other forces acting on the crate?
A) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate
perpendicular to the inclined ramp.
B) The force of static friction is the only force acting on the crate,
and it is responsible for keeping the crate at rest.
C) The magnitude of the force of static friction is equal to the
magnitude of the normal force acting on the crate.
D) The magnitude of the force of static friction is equal to the
magnitude of the weight of the crate.
E) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate parallel to
the inclined ramp.
E) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate parallel to
the inclined ramp.
If a force always acts perpendicular to an object's direction of
motion, that force cannot change the object's kinetic energy.
A) True
,B) False
A) True
Two objects, one of mass m and the other of mass 2m, are
dropped from the top of a building. When they hit the ground
A) the heavier one will have twice the kinetic energy of the
lighter one.
B) the heavier one will have four times the kinetic energy of the
lighter one.
C) both of them will have the same kinetic energy.
D) the heavier one will have 2√ times the kinetic energy of the
lighter one.
A) the heavier one will have twice the kinetic energy of the
lighter one.
If the net work done on an object is positive, what can you
conclude about the object's motion?
A) The object is at rest; its position is constant.
B) The object is speeding up.
C) The object is moving with a constant velocity.
D) The object is slowing down.
B) The object is speeding up.
A girl throws a stone from a bridge. Consider the following ways
she might throw the stone. The speed of the stone as it leaves
, her hand is the same in each case, and air resistance is
negligible. Case A: Thrown straight up.Case B: Thrown straight
down.Case C: Thrown out at an angle of 45° above horizontal.
Case D: Thrown straight out horizontally. Case E: The speed will
be the same in all cases.In which case will the speed of the stone
be greatest when it hits the water below?
A) Case A
B) Case B
C) Case C
D) Case D
E) The speed will be the same in all cases.
E) The speed will be the same in all cases.
Block 1 and block 2 have the same mass, m, and are released
from the top of two inclined planes of the same height making
30° and 60° angles with the horizontal direction, respectively. If
the coefficient of friction is the same in both cases, which of the
blocks is going faster when it reaches the bottom of its
respective incline?
A) Both blocks have the same speed at the bottom.
B) Block 2 is faster.
C) We must know the actual masses of the blocks to answer.
D) Block 1 is faster.
E) There is not enough information to answer the question
because we do not know the value of the coefficient of kinetic
friction.
B) Block 2 is faster.
A+ 2025/2026
An object is hanging by a string from the ceiling of an elevator.
The elevator is slowing down while moving upward. What is the
magnitude of the tension in the string?
A) The tension in the string is zero.
B) The magnitude of the tension in the string is less than the
magnitude of the weight of the object.
C) The magnitude of the tension in the string is greater than the
magnitude of the weight of the object.
D) The magnitude of the tension in the string is equal to the
magnitude of the weight of the object.
E) The tension in the string cannot be determined without
knowing the speed of the elevator.
B) The magnitude of the tension in the string is less than the
magnitude of the weight of the object.
Two objects have masses m and 5m, respectively. They both are
placed side by side on a frictionless inclined plane and allowed to
slide down from rest.
A) It takes the heavier object 5 times longer to reach the bottom
of the incline than the lighter object.
B) It takes the lighter object 10 times longer to reach the bottom
of the incline than the heavier object.
C) It takes the heavier object 10 times longer to reach the bottom
of the incline than the lighter object.
D) It takes the lighter object 5 times longer to reach the bottom
of the incline than the heavier object.
,E) The two objects reach the bottom of the incline at the same
time.
E) The two objects reach the bottom of the incline at the same
time.
A packing crate is sitting at rest on an inclined loading ramp.
How does the magnitude of the force of static friction compare to
the other forces acting on the crate?
A) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate
perpendicular to the inclined ramp.
B) The force of static friction is the only force acting on the crate,
and it is responsible for keeping the crate at rest.
C) The magnitude of the force of static friction is equal to the
magnitude of the normal force acting on the crate.
D) The magnitude of the force of static friction is equal to the
magnitude of the weight of the crate.
E) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate parallel to
the inclined ramp.
E) The magnitude of the force of static friction is equal to the
magnitude of the component of the weight of the crate parallel to
the inclined ramp.
If a force always acts perpendicular to an object's direction of
motion, that force cannot change the object's kinetic energy.
A) True
,B) False
A) True
Two objects, one of mass m and the other of mass 2m, are
dropped from the top of a building. When they hit the ground
A) the heavier one will have twice the kinetic energy of the
lighter one.
B) the heavier one will have four times the kinetic energy of the
lighter one.
C) both of them will have the same kinetic energy.
D) the heavier one will have 2√ times the kinetic energy of the
lighter one.
A) the heavier one will have twice the kinetic energy of the
lighter one.
If the net work done on an object is positive, what can you
conclude about the object's motion?
A) The object is at rest; its position is constant.
B) The object is speeding up.
C) The object is moving with a constant velocity.
D) The object is slowing down.
B) The object is speeding up.
A girl throws a stone from a bridge. Consider the following ways
she might throw the stone. The speed of the stone as it leaves
, her hand is the same in each case, and air resistance is
negligible. Case A: Thrown straight up.Case B: Thrown straight
down.Case C: Thrown out at an angle of 45° above horizontal.
Case D: Thrown straight out horizontally. Case E: The speed will
be the same in all cases.In which case will the speed of the stone
be greatest when it hits the water below?
A) Case A
B) Case B
C) Case C
D) Case D
E) The speed will be the same in all cases.
E) The speed will be the same in all cases.
Block 1 and block 2 have the same mass, m, and are released
from the top of two inclined planes of the same height making
30° and 60° angles with the horizontal direction, respectively. If
the coefficient of friction is the same in both cases, which of the
blocks is going faster when it reaches the bottom of its
respective incline?
A) Both blocks have the same speed at the bottom.
B) Block 2 is faster.
C) We must know the actual masses of the blocks to answer.
D) Block 1 is faster.
E) There is not enough information to answer the question
because we do not know the value of the coefficient of kinetic
friction.
B) Block 2 is faster.
