PHY 101 Midterm Exam Questions Answered Correctly Latest Update 2025-2026
How did Aristotle describe the state of motion of the Earth - AnswersEarth has natural motion
downward toward the center
What was Galileo's understanding of friction - AnswersWhen there was less friction, the motion
of objects persisted for a longer time; the less the friction, the more the motion approached
constant speed. He reasoned that, in the absence of friction or other opposing forces, a
horizontally moving object would continue moving indefinitely
Law of Inertia; Newton's First Law - AnswersEvery object continues in a state of rest or of
uniform speed in a straight line unless acted on by net external force.
How does an object move in the absence of force - AnswersIn the absence of external net
forces, sometimes called unbalanced forces, a moving object tends to move along a straight-
line path indefinitely.
Mechanical equilibrium - AnswersThe state of an object or system of objects for which there are
no changes in motion
How is weight measured using a scale - AnswersThe force with which you push down on the
scale is due to gravity, your weight, which has the same magnitude as the floor's upward
support force. When you are in equilibrium your weight equals the force of gravity acting on you
When a force acting on an object is net zero does that mean that object is at rest? Why or why
not? - AnswersA zero net force on an object doesn't mean that the object must be at rest, but
that its state of motion remains unchanged. It can be at rest or moving uniformly in a straight
line
What is the net force acting on an object that is in dynamic equilibrium - AnswersIf it moves at a
steady speed in a straight-line path, it is in dynamic equilibrium. This tells us that more than one
force acts—likely the force of friction between the crate and the floor. The fact that the net force
on the crate equals zero means that the force of friction must be equal and opposite to our
pushing force.
What is the net force acting on an object that is in static equilibrium - AnswersIf an object is in
static equilibrium, all acting forces always balance to zero
Can you explain why Earth moves at 30km/s but when you jump in the air, you stay with the
motion of Earth - AnswersObject in motion remains in motion
Motion is relative - AnswersEverything moves—even things that appear to be at rest
What is the formula for Speed - Answersspeed = distance/time
Instantaneous speed - AnswersSpeed at a specific instant in time
, Average Speed - AnswersThe overall rate of speed at which an object moves; calculated by
dividing the total distance an object travels by the total time. total distance/Time interval
Velocity - AnswersThe speed and direction of a moving object
What is a quantity that identifies direction and magnitude - AnswersVector Quantity
What if it's a quantity that only describes magnitude - AnswersScalar Quantity
Constant velocity - AnswersConstant speed and direction
Changing Velocity - AnswersChanging speed, direction, or both
The car on the circular track may have a constant speed, but its velocity is changing every
instant. Why? - Answers"She moves at a constant velocity."/
Both cars have the same speed, but they have opposite velocities because they are moving in
opposite directions.
Formula for acceleration - AnswersChange of velocity/ time interval= acceleration
If a runner goes from rest to 10 m/h in 10 s, what is their acceleration - Answers1
Explain how Galileo used slopes to understand acceleration - AnswersThe steeper the slope of
the incline, the greater the acceleration of the ball
When is an object considered in free fall - AnswersWhen a falling object is free of all
restraints—no friction, with the air or otherwise—and falls under the influence of gravity alone
Explain why g changes depending on the location of the object - Answersg varies slightly in
different locations, with an average value equal to 9.8 meters per second each second or, in
shorter notation,
Units of measure for acceleration - Answers10 m/s^2
What is the difference between velocity and speed - AnswersWhereas speed is a measure of
"how fast," velocity is a measure of both "how fast" and "in which direction."
What causes an object to accelerate - AnswersUnbalanced forces acting on an object cause the
object to accelerate.
What must you increase for acceleration to increase - AnswersMore Force
Is friction a type of force - AnswersFriction exerts a force in the direction opposite of the motion
-On object that is moving towards the right has friction from _______ - AnswersLeft
Is there friction when an object is at rest - AnswersNO
How did Aristotle describe the state of motion of the Earth - AnswersEarth has natural motion
downward toward the center
What was Galileo's understanding of friction - AnswersWhen there was less friction, the motion
of objects persisted for a longer time; the less the friction, the more the motion approached
constant speed. He reasoned that, in the absence of friction or other opposing forces, a
horizontally moving object would continue moving indefinitely
Law of Inertia; Newton's First Law - AnswersEvery object continues in a state of rest or of
uniform speed in a straight line unless acted on by net external force.
How does an object move in the absence of force - AnswersIn the absence of external net
forces, sometimes called unbalanced forces, a moving object tends to move along a straight-
line path indefinitely.
Mechanical equilibrium - AnswersThe state of an object or system of objects for which there are
no changes in motion
How is weight measured using a scale - AnswersThe force with which you push down on the
scale is due to gravity, your weight, which has the same magnitude as the floor's upward
support force. When you are in equilibrium your weight equals the force of gravity acting on you
When a force acting on an object is net zero does that mean that object is at rest? Why or why
not? - AnswersA zero net force on an object doesn't mean that the object must be at rest, but
that its state of motion remains unchanged. It can be at rest or moving uniformly in a straight
line
What is the net force acting on an object that is in dynamic equilibrium - AnswersIf it moves at a
steady speed in a straight-line path, it is in dynamic equilibrium. This tells us that more than one
force acts—likely the force of friction between the crate and the floor. The fact that the net force
on the crate equals zero means that the force of friction must be equal and opposite to our
pushing force.
What is the net force acting on an object that is in static equilibrium - AnswersIf an object is in
static equilibrium, all acting forces always balance to zero
Can you explain why Earth moves at 30km/s but when you jump in the air, you stay with the
motion of Earth - AnswersObject in motion remains in motion
Motion is relative - AnswersEverything moves—even things that appear to be at rest
What is the formula for Speed - Answersspeed = distance/time
Instantaneous speed - AnswersSpeed at a specific instant in time
, Average Speed - AnswersThe overall rate of speed at which an object moves; calculated by
dividing the total distance an object travels by the total time. total distance/Time interval
Velocity - AnswersThe speed and direction of a moving object
What is a quantity that identifies direction and magnitude - AnswersVector Quantity
What if it's a quantity that only describes magnitude - AnswersScalar Quantity
Constant velocity - AnswersConstant speed and direction
Changing Velocity - AnswersChanging speed, direction, or both
The car on the circular track may have a constant speed, but its velocity is changing every
instant. Why? - Answers"She moves at a constant velocity."/
Both cars have the same speed, but they have opposite velocities because they are moving in
opposite directions.
Formula for acceleration - AnswersChange of velocity/ time interval= acceleration
If a runner goes from rest to 10 m/h in 10 s, what is their acceleration - Answers1
Explain how Galileo used slopes to understand acceleration - AnswersThe steeper the slope of
the incline, the greater the acceleration of the ball
When is an object considered in free fall - AnswersWhen a falling object is free of all
restraints—no friction, with the air or otherwise—and falls under the influence of gravity alone
Explain why g changes depending on the location of the object - Answersg varies slightly in
different locations, with an average value equal to 9.8 meters per second each second or, in
shorter notation,
Units of measure for acceleration - Answers10 m/s^2
What is the difference between velocity and speed - AnswersWhereas speed is a measure of
"how fast," velocity is a measure of both "how fast" and "in which direction."
What causes an object to accelerate - AnswersUnbalanced forces acting on an object cause the
object to accelerate.
What must you increase for acceleration to increase - AnswersMore Force
Is friction a type of force - AnswersFriction exerts a force in the direction opposite of the motion
-On object that is moving towards the right has friction from _______ - AnswersLeft
Is there friction when an object is at rest - AnswersNO
