Question 1

A child pulls on a wagon with a horizontal force of   If the wagon moves horizontally a total of   in   what is the average power generated by the child?

Accepted Answer

A) 18 W 
B) 22 W 
C) 24 W 
D) 27 W 
A) 18 W 
B) 22 W 
C) 24 W 
D) 27 W

Question 2

The force on a 3.00-kg object as a function of position is shown in the figure.If an object is moving at 2.50 m/s when it is located at x = 2.00 m,what will its speed be when it reaches x = 8.00 m? (Assume that the numbers on the graph are accurate to 3 significant figures.)

Accepted Answer

A) 3.25 m/s 
B) 3.70 m/s 
C) 4.10 m/s 
D) 2.90 m/s 
E) 4.50 m/s 
A) 3.25 m/s 
B) 3.70 m/s 
C) 4.10 m/s 
D) 2.90 m/s 
E) 4.50 m/s

Question 3

The angle between vector   = 2.00   + 3.00   and vector   is   The scalar product of vectors   and   is 3.00.If the x component of vector   is positive,what is vector   .

Accepted Answer

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

Question 4

A student slides her 80.0-kg desk across the level floor of her dormitory room a distance 4.00 m at constant speed.If the coefficient of kinetic friction between the desk and the floor is 0.400,how much work did she do?

Accepted Answer

A) 128 J 
B) 3.14 kJ 
C) 26.7 J 
D) 1.26 kJ 
E) 24.0 J 
A) 128 J 
B) 3.14 kJ 
C) 26.7 J 
D) 1.26 kJ 
E) 24.0 J

Question 5

Find the net work done by friction on the body of a snake slithering in a complete circle of   radius.The coefficient of friction between the ground and the snake is 0.25,and the snake's weight is

Accepted Answer

A) -330 J 
B) 0 J 
C) -3300 J 
D) -670 J 
A) -330 J 
B) 0 J 
C) -3300 J 
D) -670 J

Question 6

In the figure,a 900-kg crate is on a rough surface inclined at 30°.A constant external force   is applied horizontally to the crate.While this force pushes the crate a distance of 3.0 m up the incline,its velocity changes from 1.2 m/s to 2.3 m/s.How much work does friction do during this process?

Accepted Answer

A) -3700 J 
B) -7200 J 
C) +3700 J 
D) +7200 J 
E) zero 
A) -3700 J 
B) -7200 J 
C) +3700 J 
D) +7200 J 
E) zero

Question 7

You slam on the brakes of your car in a panic,and skid a certain distance on a straight,level road.If you had been traveling twice as fast,what distance would the car have skidded,under identical conditions?

Accepted Answer

A) It would have skidded 4 times farther. 
B) It would have skidded 2 times farther. 
C) It would have skidded   times farther. 
D) It would have skidded 1/   times farther. 
E) It would have skidded 1/2 as far. 
A) It would have skidded 4 times farther. 
B) It would have skidded 2 times farther. 
C) It would have skidded   times farther. 
D) It would have skidded 1/   times farther. 
E) It would have skidded 1/2 as far.

Question 8

Determine the angle between the directions of vector   = 3.00   + 1.00   and vector   = -3.00   + 3.00   .

Accepted Answer

A) 26.6° 
B) 30.0° 
C) 88.1° 
D) 117° 
E) 45.2° 
A) 26.6° 
B) 30.0° 
C) 88.1° 
D) 117° 
E) 45.2°

Question 9

For the vectors shown in the figure,assume numbers are accurate to two significant figures.The scalar product   ×   is closest to

Accepted Answer

A) zero. 
B) 16. 
C) 45. 
D) -16. 
E) -45. 
A) zero. 
B) 16. 
C) 45. 
D) -16. 
E) -45.

Question 10

Two men,Joel and Jerry,push against a wall.Jerry stops after 10 min,while Joel is able to push for 5.0 min longer.Compare the work they do.

Accepted Answer

A) Both men do positive work,but Joel does 75% more work than Jerry. 
B) Both men do positive work,but Joel does 50% more work than Jerry. 
C) Both men do positive work,but Jerry does 50% more work than Joel. 
D) Both men do positive work,but Joel does 25% more work than Jerry. 
E) Neither of them does any work. 
A) Both men do positive work,but Joel does 75% more work than Jerry. 
B) Both men do positive work,but Joel does 50% more work than Jerry. 
C) Both men do positive work,but Jerry does 50% more work than Joel. 
D) Both men do positive work,but Joel does 25% more work than Jerry. 
E) Neither of them does any work.

Question 11

An object is acted upon by a force that represented by the force vs.position graph in the figure.What is the work done as the object moves
(a)from 4 m to 6 m?
(b)from 6 m to 12 m?

Accepted Answer

The answer of An object is acted upon by a...

Question 12

A traveler pulls on a suitcase strap at an angle 36° above the horizontal.If   of work are done by the strap while moving the suitcase a horizontal distance of 15 m,what is the tension in the strap?

Accepted Answer

A) 75 N 
B) 61 N 
C) 85 N 
D) 92 N 
A) 75 N 
B) 61 N 
C) 85 N 
D) 92 N

Question 13

Block A (0.40 kg)and block B (0.30 kg)are on a frictionless table (see figure).Spring 1 connects block A to a frictionless peg at 0 and spring 2 connects block A and block B.When the blocks are in uniform circular motion about 0,the springs have lengths of 0.60 m and 0.40 m,as shown.The springs are ideal and massless,and the linear speed of block B is 2.0 m/s.If the spring constant of spring 1 is equal to 30 N/m,the unstretched length of spring 1 is closest to

Accepted Answer

A) 0.51 m. 
B) 0.52 m. 
C) 0.53 m. 
D) 0.54 m. 
E) 0.55 m. 
A) 0.51 m. 
B) 0.52 m. 
C) 0.53 m. 
D) 0.54 m. 
E) 0.55 m.

Question 14

A force on a particle depends on position such that F(x)= (3.00 N/   )   + (6.00 N/m)x for a particle constrained to move along the x-axis.What work is done by this force on a particle that moves from x = 0.00 m to x = 2.00 m?

Accepted Answer

A) 10.0 J 
B) 20.0 J 
C) -48.0 J 
D) 24.0 J 
E) 48.0 J 
A) 10.0 J 
B) 20.0 J 
C) -48.0 J 
D) 24.0 J 
E) 48.0 J

Question 15

In the figure,a 700-kg crate is on a rough surface inclined at 30°.A constant external force P = 5600 N is applied horizontally to the crate.As the force pushes the crate a distance of 3.00 m up the incline,the speed changes from 1.40 m/s to 2.50 m/s.How much work does gravity do on the crate during this process?

Accepted Answer

A) -10,300 J 
B) -3400 J 
C) +10,300 J 
D) +3400 J 
E) zero 
A) -10,300 J 
B) -3400 J 
C) +10,300 J 
D) +3400 J 
E) zero

Question 16

If two nonzero vectors point in the same direction,their dot product must be zero.

Accepted Answer

A) True 
 B)False

Question 17

Calculate the minimum average power output necessary for a   person to run up a 12.0 m long hillside,which is inclined at 25.0° above the horizontal,in 3.00 s.You can neglect the person's kinetic energy.Express your answer in horsepower.(1 hp = 746 W)

Accepted Answer

A) 1.24 hp 
B) 2.93 hp 
C) 1.86 hp 
D) 0.740 hp 
A) 1.24 hp 
B) 2.93 hp 
C) 1.86 hp 
D) 0.740 hp

Question 18

A graph of the force on an object as a function of its position is shown in the figure.Determine the amount of work done by this force on an object that moves from x = 1.0 m to x = 6.0 m.(Assume an accuracy of 2 significant figures for the numbers on the graph.)

Accepted Answer

A) 26 J 
B) 29 J 
C) 22 J 
D) 35 J 
E) 27 J 
A) 26 J 
B) 29 J 
C) 22 J 
D) 35 J 
E) 27 J

Question 19

A graph of the force on an object as a function of its position is shown in the figure.Determine the amount of work done by this force on the object during a displacement from x = -2.00 m to x = 2.00 m.(Assume an accuracy of 3 significant figures for the numbers
On the graph.)

Accepted Answer

A) -12.0 J 
B) -3.00 J 
C) -1.00 J 
D) 12.0 J 
E) 3.00 J 
A) -12.0 J 
B) -3.00 J 
C) -1.00 J 
D) 12.0 J 
E) 3.00 J

Question 20

Three forces,F1 = 20.0 N,F2 = 40.0 N,and F3 = 10.0 N act on an object with a mass of 2.00 kg which can move along a frictionless inclined plane as shown in the figure.The questions refer to the instant when the object has moved through a distance of 0.600 m along the surface of the inclined plane in the upward direction.Calculate the amount of work done by
(a)F1
(b)F2
(c)F3.

Accepted Answer

(a)12.0 J

Exam 9: Work and Kinetic Energy

A child pulls on a wagon with a horizontal force of If the wagon moves horizontally a total of in what is the average power generated by the child?

The force on a 3.00-kg object as a function of position is shown in the figure.If an object is moving at 2.50 m/s when it is located at x = 2.00 m,what will its speed be when it reaches x = 8.00 m? (Assume that the numbers on the graph are accurate to 3 significant figures.)

The angle between vector = 2.00 + 3.00 and vector is The scalar product of vectors and is 3.00.If the x component of vector is positive,what is vector .

A student slides her 80.0-kg desk across the level floor of her dormitory room a distance 4.00 m at constant speed.If the coefficient of kinetic friction between the desk and the floor is 0.400,how much work did she do?

Find the net work done by friction on the body of a snake slithering in a complete circle of radius.The coefficient of friction between the ground and the snake is 0.25,and the snake's weight is

In the figure,a 900-kg crate is on a rough surface inclined at 30°.A constant external force is applied horizontally to the crate.While this force pushes the crate a distance of 3.0 m up the incline,its velocity changes from 1.2 m/s to 2.3 m/s.How much work does friction do during this process?

You slam on the brakes of your car in a panic,and skid a certain distance on a straight,level road.If you had been traveling twice as fast,what distance would the car have skidded,under identical conditions?

Determine the angle between the directions of vector = 3.00 + 1.00 and vector = -3.00 + 3.00 .

For the vectors shown in the figure,assume numbers are accurate to two significant figures.The scalar product × is closest to

Two men,Joel and Jerry,push against a wall.Jerry stops after 10 min,while Joel is able to push for 5.0 min longer.Compare the work they do.

An object is acted upon by a force that represented by the force vs.position graph in the figure.What is the work done as the object moves (a)from 4 m to 6 m? (b)from 6 m to 12 m?

A traveler pulls on a suitcase strap at an angle 36° above the horizontal.If of work are done by the strap while moving the suitcase a horizontal distance of 15 m,what is the tension in the strap?

A force on a particle depends on position such that F(x)= (3.00 N/ ) + (6.00 N/m)x for a particle constrained to move along the x-axis.What work is done by this force on a particle that moves from x = 0.00 m to x = 2.00 m?

If two nonzero vectors point in the same direction,their dot product must be zero.

Calculate the minimum average power output necessary for a person to run up a 12.0 m long hillside,which is inclined at 25.0° above the horizontal,in 3.00 s.You can neglect the person's kinetic energy.Express your answer in horsepower.(1 hp = 746 W)

A graph of the force on an object as a function of its position is shown in the figure.Determine the amount of work done by this force on an object that moves from x = 1.0 m to x = 6.0 m.(Assume an accuracy of 2 significant figures for the numbers on the graph.)

A graph of the force on an object as a function of its position is shown in the figure.Determine the amount of work done by this force on the object during a displacement from x = -2.00 m to x = 2.00 m.(Assume an accuracy of 3 significant figures for the numbers On the graph.)

Concepts of Motion

Kinematics in One Dimension

Vectors and Coordinate Systems

Kinematics in Two Dimensions

Force and Motion

Dynamics I: Motion Along a Line

Newtons Third Law

Dynamics II: Motion in a Plane

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