AP Physics 1: Algebra-Based Practice Quiz: Newton's First Law
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 11 questions to check your progress.
Question 1 of 11
All Questions (11)
A) The velocity of the system will increase.
B) The velocity of the system will decrease to zero.
C) The velocity of the system will remain constant.
D) The system will immediately stop moving.
Correct Answer: C
Newton's first law explicitly states that if the net force exerted on a system is zero, the velocity of that system will remain constant. This means it will not change its speed or direction.
A) The strongest force acting on the system.
B) The vector sum of all forces exerted on the system.
C) The arithmetic average of all forces on the system.
D) The force required to keep the system at rest.
Correct Answer: B
The provided content defines the net force on a system as the vector sum of all forces exerted on it. This means both the magnitude and direction of each force are considered.
A) There are no forces acting on the system.
B) The forces acting on the system are all equal in magnitude.
C) The net force exerted on the system is zero.
D) A single, constant force is acting on the system.
Correct Answer: C
The definition of translational equilibrium is a configuration of forces where the net force exerted on a system is zero. This is the condition required for Newton's first law to apply.
A) The net force is zero.
B) The net force is constant and in the direction of motion.
C) The net force is increasing.
D) The net force is opposing the motion.
Correct Answer: A
Newton's first law states that a constant velocity is maintained if and only if the net force on the system is zero. Therefore, observing a constant velocity implies a zero net force.
A) It is a frame where all objects are at rest.
B) It is a frame from which an observer would verify Newton's first law of motion.
C) It is a frame that is accelerating at a constant rate.
D) It is a frame where the net force on every object is always non-zero.
Correct Answer: B
The provided content defines an inertial reference frame as one from which an observer would verify that an object's velocity remains constant if the net force on it is zero, which is the statement of Newton's first law.
A) The system must have zero mass.
B) The system must be in a vacuum.
C) The system must be in translational equilibrium.
D) The system must be acted upon by a single force.
Correct Answer: C
A system's velocity remains constant if the net force is zero. The term for this state is 'translational equilibrium'. Therefore, being in translational equilibrium is the condition for constant velocity.
A) The system has no forces acting on it.
B) The net force exerted on the system is not zero.
C) The system is in translational equilibrium.
D) The observer is in a perfect inertial reference frame.
Correct Answer: B
Newton's first law implies its contrapositive: if the velocity of a system is not constant (i.e., it is changing), then the net force exerted on the system cannot be zero.
A) Only the magnitudes of the forces are added arithmetically.
B) Forces acting in opposite directions are ignored.
C) The direction of each force is as important as its magnitude.
D) The net force is always equal to the largest individual force.
Correct Answer: C
A 'vector sum' requires consideration of both the magnitude (strength) and the direction of each force. Forces can cancel each other out if they are equal in magnitude and opposite in direction.
A) The laboratory is a perfect example of translational equilibrium.
B) The laboratory is not an inertial reference frame.
C) Newton's first law does not apply to the cart.
D) The laboratory must be at a location with zero gravity.
Correct Answer: B
An inertial reference frame is one where Newton's first law is observed to be true. Since the law appears to be violated (acceleration with zero net force), the observer's frame of reference (the laboratory) must be non-inertial (for example, it could be accelerating).
A) Mass and acceleration.
B) A zero net force and a constant velocity.
C) A non-zero net force and a constant velocity.
D) Translational equilibrium and changing velocity.
Correct Answer: B
Newton's first law establishes a direct relationship between the condition of a zero net force (which is also called translational equilibrium) and the resulting state of constant velocity.
A) The force of the push is the only force acting on the box.
B) The net force on the box is in the direction of motion.
C) The box is not in translational equilibrium.
D) The vector sum of all forces on the box is zero.
Correct Answer: D
The key information is 'constant velocity'. According to Newton's first law, if the velocity is constant, the net force must be zero. The net force is defined as the vector sum of all forces. Therefore, the vector sum of all forces (the push, friction, gravity, normal force) must be zero.