Question 1

The figure shows a graph of the acceleration of a 125-g object as a function of the net force acting on it. What is the acceleration at points A and B?

Accepted Answer

A: 16 M/S²,

Question 2

The graph in the figure shows the x component of the acceleration of a 2.4-kg object as a function of time (in ms).   (a) At what time(s) does the x component of the net force on the object reach its maximum magnitude, and what is that maximum magnitude?
(b) What is the x component of the net force on the object at time t = 0.0 ms and at t = 4.0 ms?

Accepted Answer

(a) At 3.0

Question 3

A 615 N student standing on a scale in an elevator notices that the scale reads 645 N. From this information, the student knows that the elevator must be moving

Accepted Answer

A)  downward. 
B)  upward. 
C)  You cannot tell if it is moving upward or downward. 
A)  downward. 
B)  upward. 
C)  You cannot tell if it is moving upward or downward.

Question 4

The figure shows two forces acting at right angles on an object. They have magnitudes   = 6.3 N and   = 2.1 N. What third force will cause the object to be in equilibrium (acceleration equals zero)?

Accepted Answer

A)  6.6 N at 162° counterclockwise from   1 
B)  6.6 N at 108° counterclockwise from   1 
C)  4.2 N at 162° counterclockwise from   1 
D)  4.2 N at 108° counterclockwise from   1 
A)  6.6 N at 162° counterclockwise from   1 
B)  6.6 N at 108° counterclockwise from   1 
C)  4.2 N at 162° counterclockwise from   1 
D)  4.2 N at 108° counterclockwise from   1

Question 5

You are standing in a moving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. The force acting on you that causes you to fall forward is

Accepted Answer

A)  the force of gravity. 
B)  the normal force due to your contact with the floor of the bus. 
C)  the force due to static friction between you and the floor of the bus. 
D)  the force due to kinetic friction between you and the floor of the bus. 
E)  No forces were acting on you to cause you to fall. 
A)  the force of gravity. 
B)  the normal force due to your contact with the floor of the bus. 
C)  the force due to static friction between you and the floor of the bus. 
D)  the force due to kinetic friction between you and the floor of the bus. 
E)  No forces were acting on you to cause you to fall.

Question 6

The figure shows two forces, each of magnitude 4.6 N, acting on an object. The angle between these forces is 40°, and they make equal angles above and below the horizontal. What third force will cause the object to be in equilibrium (acceleration equals zero)?

Accepted Answer

A)  8.6 N pointing to the right 
B)  7.0 N pointing to the right 
C)  4.3 N pointing to the right 
D)  3.5 N pointing to the right 
A)  8.6 N pointing to the right 
B)  7.0 N pointing to the right 
C)  4.3 N pointing to the right 
D)  3.5 N pointing to the right

Question 7

Point P in the figure indicates the position of an object traveling at constant speed clockwise around the circle. Which arrow best represent the direction the object would travel if the net external force on it were suddenly reduced to zero?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 8

Which one of the following free-body diagrams best represents the free-body diagram, with correct relative force magnitudes, of a person in an elevator that is traveling upward with an unchanging velocity?   f is the force of the floor on the person and   g is the force of gravity on the person.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 9

A ball is tossed vertically upward. When it reaches its highest point (before falling back downward)

Accepted Answer

A)  the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward. 
B)  the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is zero. 
C)  the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is directed downward. 
D)  the velocity and acceleration reverse direction, but the force of gravity on the ball remains downward. 
E)  the velocity, acceleration, and the force of gravity on the ball all reverse direction. 
A)  the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward. 
B)  the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is zero. 
C)  the velocity is zero, the acceleration is zero, and the force of gravity acting on the ball is directed downward. 
D)  the velocity and acceleration reverse direction, but the force of gravity on the ball remains downward. 
E)  the velocity, acceleration, and the force of gravity on the ball all reverse direction.

Question 10

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point down the ramp.

Accepted Answer

A)  True 
B)  False 
A)  True 
B)  False

Exam 5: Force and Motion

The figure shows a graph of the acceleration of a 125-g object as a function of the net force acting on it. What is the acceleration at points A and B?

A 615 N student standing on a scale in an elevator notices that the scale reads 645 N. From this information, the student knows that the elevator must be moving

The figure shows two forces acting at right angles on an object. They have magnitudes = 6.3 N and = 2.1 N. What third force will cause the object to be in equilibrium (acceleration equals zero)?

You are standing in a moving bus, facing forward, and you suddenly fall forward as the bus comes to an immediate stop. The force acting on you that causes you to fall forward is

The figure shows two forces, each of magnitude 4.6 N, acting on an object. The angle between these forces is 40°, and they make equal angles above and below the horizontal. What third force will cause the object to be in equilibrium (acceleration equals zero)?

Point P in the figure indicates the position of an object traveling at constant speed clockwise around the circle. Which arrow best represent the direction the object would travel if the net external force on it were suddenly reduced to zero?

Which one of the following free-body diagrams best represents the free-body diagram, with correct relative force magnitudes, of a person in an elevator that is traveling upward with an unchanging velocity? f is the force of the floor on the person and g is the force of gravity on the person.

A ball is tossed vertically upward. When it reaches its highest point (before falling back downward)

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point down the ramp.

Concepts of Motion

Kinematics in One Dimension

Vectors and Coordinate Systems

Kinematics in Two Dimensions

Dynamics I: Motion Along a Line

Newtons Third Law

Dynamics Ii: Motion in a Plane

Work and Kinetic Energy

Interactions and Potential Energy

Impulse and Momentum

Rotation of a Rigid Body

Newtons Theory of Gravity

Fluids and Elasticity

Oscillations

Traveling Waves

Superposition

A Macroscopic Description of Matter

Work, Heat, and the First Law of Thermodynamics

The Micromacro Connection

Heat Engines and Refrigerators

Electric Charges and Forces

The Electric Field

Gausss Law

The Electric Potential

Potential and Field

Current and Resistance

Fundamentals of Circuits

The Magnetic Field

Electromagnetic Induction

Electromagnetic Fields and Waves

Ac Circuits

Wave Optics

Ray Optics

Optical Instruments

Relativity

The Foundations of Modern Physics

Quantization

Wave Functions and Uncertainty

One-Dimensional Quantum Mechanics

Atomic Physics

Nuclear Physics

Filters

Which one of the following free-body diagrams best represents the free-body diagram, with correct relative force magnitudes, of a person in an elevator that is traveling upward with an unchanging velocity? _f is the force of the floor on the person and _g is the force of gravity on the person.