A force unit is defined as the product of a mass unit and a unit of:
The gravitational force exerted on an object would most likely be represented by which force vector?
Which of the following situations describes inertia?
D. All of the above
Which of the following statements describe an object in equilibrium?
I. The object is at rest.
II. The object is moving at constant velocity.
III. The net external force on the object is zero.
C. I, II, and III
In which situation is the net force acting on a car zero?
D. The car maintains both its speed and direction
In an action-reaction pair, the
A. action force and the reaction force act on two different objects
The length of a force vector represents the
C. magnitude of the force
If a nonzero net force is acting on an object, then the object is definitely
A. being accelerated
Which statement about the acceleration of an object is correct?
A. The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object.
Centripetal acceleration must involve a change in
B. An object's velocity
What term describes a force that causes an object to move in a circular path
B. Centripetal force
A centripetal force acts
C. Perpendicular to tangential speed but in the same plane
What is the centripetal force that holds planets in orbit?
B. Kepler's force
The speed of an object orbiting another object depends on:
B. The mass of the object being orbited and the distance between the objects
The centripetal force on an object in circular motion is:
C. In the same direction as the centripetal acceleration
When an astronaut in orbit experiences apparent weightlessness,
D. The net gravitational force on the astronaut is not balanced by a normal force
If an object starts to accelerate,
C. An unbalanced force is acting on it
The tendency to resist a change in an objects motion is:
When forces are balanced, the total force:
A. Is zero
Newton's first law of motion explains:
The reaction force occurs _______ the action force.
Which describes how velocity changes with time?
A person who is not wearing a seat belt is involved in a head-on car crash. They continue to move forwards because of:
What is the term for speed at any instant in time?
D. Instantaneous speed
Newton's first law of motion states that an object stays at rest unless a(n) ________ acts on it.
C. Unbalanced force
Which of the following objects has the greatest inertia?
A. Bowling ball
A force is which one of these?
D. A push or pull
Force is measured in which unit?
A force is exerted on a box and an equal and opposite force is exerted by the box. What explains this?
D. Newton's third law of motion
Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upwards along a y-axis.)
C. A cat jumps from a tree limb to the ground
Suppose you are given a position vs. time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
B. Instantaneous velocity
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
A. The car slows down
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
C. The car speeds up
Acceleration due to gravity is also called:
B. Free-fall acceleration
Which of the following statements applies to the motion of a ball rising and then falling in free fall?
I. The ball has constant acceleration as it moves upward.
II. The ball has constant acceleration at the top of its path.
III. The ball has constant acceleration as it moves downward.
B. I, II, and III
A baseball catcher throws a ball vertically upwards and catches it in the same spot as it returns to his glove. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
A. At the top of its path
When there is no air resistance, objects of different masses dropped form rest:
B. Fall with equal accelerations and with equal displacements
Objects that are falling towards Earth in free-fall move:
D. Faster and faster
Which would hit the ground first if dropped from the same height in a vacuum- a feather or a metal bolt?
B. They would hit the ground at the same time
A dog walks from +4 m to +2 m. Which of the following statements is true about the dog's motion?