MCQ questions and answers
A ball of mass 0.4 kg is initially at rest on the ground. It is kicked and leaves the kicker's foot with a speed
of 5.0 m/s in a direction 60° above the horizontal. The magnitude of the impulse imparted by the ball to
the foot is most nearly ✔✔2 N*s
A force of constant magnitude F and fixed direction acts on an object of mass m that is initially at rest. If
the force acts for a time interval ∆t over a displacement ∆x , what is the magnitude of the resultant
change in the linear momentum of the object? ✔✔FΔt
A person applies an impulse of 5.0 kg∙m/s to a box in order to set it in motion. If the person is in contact
with the box for 0.25 s, what is the average force exerted by the person on the box? ✔✔20.0N
An object of known mass M with speed vo travels toward a wall. The obje
ct collides with it and bounces away from the wall in the opposite direction in which the object was
initially traveling. The wall exerts an average force Fo on the object during the collision. A student must
use the equation \Delta p=F\Delta tΔp=FΔt to determine the change in momentum of the object from
immediately before the collision to immediately after the collision. Which side of the equation could the
student use to determine the change of the object's momentum? ✔✔Neither side of the equation may
be used because there are too many unknown quantities before, during, and after the collision.
In an experiment, an object is released from rest near and above Earth's surface. A student must
determine the relationship between the direction of the gravitational force exerted on the object and
the change in momentum caused by that force. What data could the student collect to determine the
magnitude and direction of the gravitational force and the change in momentum of the object? Justify
your choices. Select two answers. ✔✔The mass of the object, because it is required to determine the
force due to gravity exerted on the object, and the velocity of the object the instant before it reaches
Earth's surface, because it is required to determine the change in velocity of the object.
The mass of the object, because it is required to determine the force due to gravity exerted on the
object, and the distance fallen by the object, because the force is exerted during the entire falling
distance.
A student conducts an experiment in which an object travels across a horizontal surface while for 2s a
net force is applied to a 2 kg object that initially travels with a speed of 0.5 m/s. Data collected from the
experiment are used to create the graph of the magnitude of the applied force exerted on the object as
, a function of time is shown. All frictional forces are considered to be negligible. Can the student use the
graph and the known data to determine the momentum of the object after the force has been applied?
✔✔No, because the student needs to know the direction that the force is applied to the object because
the applied force will be in the same direction as the change in momentum of the object.
Cart A with a mass of 2.0 kg travels at a constant speed of 3.0 m/s to the right on a horizontal surface, as
shown in the figure. Cart A then collides with cart B with a mass of 1.5 kg that is initially at rest...
✔✔Equation 1 and Equation 2
An object of mass 2 kg collides with an object of mass 1 kg that is at rest, as shown in the figure. A graph
of the force as a function of time that the 1 kg object exerts on the 2 kg object is shown. ✔✔(2 kg)
(2m/s-v0)=1/2(8000 N)(0.00125 s)
How does an air mattress protect a stunt person landing on the ground after a stunt? ✔✔It lengthens
the stopping time of the stunt person and reduces the force applied during the landing.
Ball X of mass 1.0 kg and ball Y of mass .5 kg travel toward each other on a horizontal surface... ✔✔ball Y
will travel at a speed greater
Assume that the collision in each scenario is elastic. A graph of the magnitude of the force exerted on
Cart Y as a function of time for scenario 1 is shown. During which interval of time does the magnitude of
the momentum of Cart Y change the most? ✔✔.004s to .006s
A student drops an object from rest above a force plate that records information about the force
exerted on the object as a function of time during the time interval in which the object is in contact with
the force plate. Which of the following measurements should the student take, in addition to the
measurements from the force plate, to determine the change in momentum of the object from
immediately before the collision to immediately after the collision? ✔✔The student has enough
information to make the determination.
The student conducts a second experiment in which the magnitude of the force exerted on block X from
block Y is measured over the time in which the collision takes place. A graph of the force as a function of
time is shown. In a third experiment, the student creates a collision such that the force exerted on block
X from block Y is constant for 0.020 s. Which of the following constant forces, if exerted on block X from
block Y, would produce the same change in momentum as is shown by the graph? ✔✔200N
A ball of mass 0.4 kg is initially at rest on the ground. It is kicked and leaves the kicker's foot with a speed
of 5.0 m/s in a direction 60° above the horizontal. The magnitude of the impulse imparted by the ball to
the foot is most nearly ✔✔2 N*s
A force of constant magnitude F and fixed direction acts on an object of mass m that is initially at rest. If
the force acts for a time interval ∆t over a displacement ∆x , what is the magnitude of the resultant
change in the linear momentum of the object? ✔✔FΔt
A person applies an impulse of 5.0 kg∙m/s to a box in order to set it in motion. If the person is in contact
with the box for 0.25 s, what is the average force exerted by the person on the box? ✔✔20.0N
An object of known mass M with speed vo travels toward a wall. The obje
ct collides with it and bounces away from the wall in the opposite direction in which the object was
initially traveling. The wall exerts an average force Fo on the object during the collision. A student must
use the equation \Delta p=F\Delta tΔp=FΔt to determine the change in momentum of the object from
immediately before the collision to immediately after the collision. Which side of the equation could the
student use to determine the change of the object's momentum? ✔✔Neither side of the equation may
be used because there are too many unknown quantities before, during, and after the collision.
In an experiment, an object is released from rest near and above Earth's surface. A student must
determine the relationship between the direction of the gravitational force exerted on the object and
the change in momentum caused by that force. What data could the student collect to determine the
magnitude and direction of the gravitational force and the change in momentum of the object? Justify
your choices. Select two answers. ✔✔The mass of the object, because it is required to determine the
force due to gravity exerted on the object, and the velocity of the object the instant before it reaches
Earth's surface, because it is required to determine the change in velocity of the object.
The mass of the object, because it is required to determine the force due to gravity exerted on the
object, and the distance fallen by the object, because the force is exerted during the entire falling
distance.
A student conducts an experiment in which an object travels across a horizontal surface while for 2s a
net force is applied to a 2 kg object that initially travels with a speed of 0.5 m/s. Data collected from the
experiment are used to create the graph of the magnitude of the applied force exerted on the object as
, a function of time is shown. All frictional forces are considered to be negligible. Can the student use the
graph and the known data to determine the momentum of the object after the force has been applied?
✔✔No, because the student needs to know the direction that the force is applied to the object because
the applied force will be in the same direction as the change in momentum of the object.
Cart A with a mass of 2.0 kg travels at a constant speed of 3.0 m/s to the right on a horizontal surface, as
shown in the figure. Cart A then collides with cart B with a mass of 1.5 kg that is initially at rest...
✔✔Equation 1 and Equation 2
An object of mass 2 kg collides with an object of mass 1 kg that is at rest, as shown in the figure. A graph
of the force as a function of time that the 1 kg object exerts on the 2 kg object is shown. ✔✔(2 kg)
(2m/s-v0)=1/2(8000 N)(0.00125 s)
How does an air mattress protect a stunt person landing on the ground after a stunt? ✔✔It lengthens
the stopping time of the stunt person and reduces the force applied during the landing.
Ball X of mass 1.0 kg and ball Y of mass .5 kg travel toward each other on a horizontal surface... ✔✔ball Y
will travel at a speed greater
Assume that the collision in each scenario is elastic. A graph of the magnitude of the force exerted on
Cart Y as a function of time for scenario 1 is shown. During which interval of time does the magnitude of
the momentum of Cart Y change the most? ✔✔.004s to .006s
A student drops an object from rest above a force plate that records information about the force
exerted on the object as a function of time during the time interval in which the object is in contact with
the force plate. Which of the following measurements should the student take, in addition to the
measurements from the force plate, to determine the change in momentum of the object from
immediately before the collision to immediately after the collision? ✔✔The student has enough
information to make the determination.
The student conducts a second experiment in which the magnitude of the force exerted on block X from
block Y is measured over the time in which the collision takes place. A graph of the force as a function of
time is shown. In a third experiment, the student creates a collision such that the force exerted on block
X from block Y is constant for 0.020 s. Which of the following constant forces, if exerted on block X from
block Y, would produce the same change in momentum as is shown by the graph? ✔✔200N
