Question 1

The value of the dot product of two vectors depends on the particular coordinate system being used.

Accepted Answer

A) True 
 B)False  False

Question 2

A car needs to generate   in order to maintain a constant velocity of   on a flat road.What is the magnitude of the total resistive force acting on the car (due to friction,air resistance,etc.)? (1 hp = 746 W)

Accepted Answer

A) 2.05 × 103 N 
B) 2.75 N 
C) 1.03 × 103 N 
D) 2.87 × 103 N 
A) 2.05 × 103 N 
B) 2.75 N 
C) 1.03 × 103 N 
D) 2.87 × 103 N A

Question 3

The scalar product of vector   = 3.00   + 2.00   and vector   is 10.0.Which of the following vectors could be vector   ?

Accepted Answer

A) 2.00   + 4.00   
B) 4.00   + 6.00   
C) 5.00   + 4.00   
D) 12.0   
E) 2.00   + 2.00   
A) 2.00   + 4.00   
B) 4.00   + 6.00   
C) 5.00   + 4.00   
D) 12.0   
E) 2.00   + 2.00   E

Question 4

A person pushes horizontally on a heavy box and slides it across the level floor at constant velocity.The person pushes with a 60.0 N force for the first   at which time he begins to tire.The force he exerts then starts to decrease linearly from 60.0 N to 0.00 N across the remaining   How much total work did the person do on the box?

Accepted Answer

A) 619 J 
B) 826 J 
C) 495 J 
D) 925 J 
A) 619 J 
B) 826 J 
C) 495 J 
D) 925 J

Question 5

A 3.00-kg ball swings rapidly in a complete vertical circle of radius 2.00 m by a light string that is fixed at one end.The ball moves so fast that the string is always taut and perpendicular to the velocity of the ball.As the ball swings from its lowest point to its highest point

Accepted Answer

A) the work done on it by gravity and the work done on it by the tension in the string are both equal to -118 J. 
B) the work done on it by gravity is -118 J and the work done on it by the tension in the string is +118 J. 
C) the work done on it by gravity is +118 J and the work done on it by the tension in the string is -118 J. 
D) the work done on it by gravity is -118 J and the work done on it by the tension in the string is zero. 
E) the work done on it by gravity and the work done on it by the tension in the string are both equal to zero. 
A) the work done on it by gravity and the work done on it by the tension in the string are both equal to -118 J. 
B) the work done on it by gravity is -118 J and the work done on it by the tension in the string is +118 J. 
C) the work done on it by gravity is +118 J and the work done on it by the tension in the string is -118 J. 
D) the work done on it by gravity is -118 J and the work done on it by the tension in the string is zero. 
E) the work done on it by gravity and the work done on it by the tension in the string are both equal to zero.

Question 6

Consider a plot of the displacement (x)as a function of the applied force (F)for an ideal elastic spring.The slope of the curve would be

Accepted Answer

A) the spring constant. 
B) the reciprocal of the spring constant. 
C) the acceleration due to gravity. 
D) the reciprocal of the acceleration of gravity. 
E) the mass of the object attached to the spring. 
A) the spring constant. 
B) the reciprocal of the spring constant. 
C) the acceleration due to gravity. 
D) the reciprocal of the acceleration of gravity. 
E) the mass of the object attached to the spring.

Question 7

A constant horizontal pull acts on a sled on a horizontal frictionless ice pond.The sled starts from rest.When the pull acts over a distance x,the sled acquires a speed v and a kinetic energy K.If the same pull instead acts over twice this distance:

Accepted Answer

A) The sled's speed will be 2v and its kinetic energy will be 2K. 
B) The sled's speed will be 2v and its kinetic energy will be K   . 
C) The sled's speed will be v   and its kinetic energy will be 2K. 
D) The sled's speed will be v   and its kinetic energy will be K   . 
E) The sled's speed will be 4v and its kinetic energy will be 2K. 
A) The sled's speed will be 2v and its kinetic energy will be 2K. 
B) The sled's speed will be 2v and its kinetic energy will be K   . 
C) The sled's speed will be v   and its kinetic energy will be 2K. 
D) The sled's speed will be v   and its kinetic energy will be K   . 
E) The sled's speed will be 4v and its kinetic energy will be 2K.

Question 8

A 1000.0 kg car is moving at   If a   truck has 18 times the kinetic energy of the car,how fast is the truck moving?

Accepted Answer

A) 45 km/h 
B) 63 km/h 
C) 54 km/h 
D) 36 km/h 
A) 45 km/h 
B) 63 km/h 
C) 54 km/h 
D) 36 km/h

Question 9

Two boys searching for buried treasure are standing underneath the same tree.One boy walks   east and then   north.The other boy walks   west and then   north.Find the scalar product of their net displacements from the tree.

Accepted Answer

The answer of Two boys searching for buried treasure are...

Question 10

A force F = bx3 acts in the x direction,where the value of b is 3.7 N/m3.How much work is done by this force in moving an object from   to

Accepted Answer

A) 42 J 
B) 13 J 
C) 50 J 
D) 57 J 
A) 42 J 
B) 13 J 
C) 50 J 
D) 57 J

Question 11

A spring stretches by   when a   object is attached.What is the weight of a fish that would stretch the spring by

Accepted Answer

A) 199 N 
B) 91.0 N 
C) 145 N 
D) 279 N 
A) 199 N 
B) 91.0 N 
C) 145 N 
D) 279 N

Question 12

A force   = 12 N   - 10 N   acts on an object.How much work does this force do as the object moves from the origin to the point

Accepted Answer

A) 46 J 
B) 266 J 
C) 37 J 
D) 62 J 
A) 46 J 
B) 266 J 
C) 37 J 
D) 62 J

Question 13

Which of the graphs in the figure represents a spring that gets less stiff the more it is stretched?

Accepted Answer

A) Graph a 
B) Graph b 
C) Graph c 
D) Graph d 
A) Graph a 
B) Graph b 
C) Graph c 
D) Graph d

Question 14

It requires 49 J of work to stretch an ideal very light spring from a length of 1.4 m to a length of 2.9 m.What is the value of the spring constant of this spring?

Accepted Answer

A) 15 N/m 
B) 44 N/m 
C) 29 N/m 
D) 22 N/m 
A) 15 N/m 
B) 44 N/m 
C) 29 N/m 
D) 22 N/m

Question 15

A 4.0-kg object is moving with speed 2.0 m/s.A 1.0-kg object is moving with speed 4.0 m/s.Both objects encounter the same constant braking force,and are brought to rest.Which object travels the greater distance before stopping?

Accepted Answer

A) the 4.0-kg object 
B) the 1.0-kg object 
C) Both objects travel the same distance. 
D) It is impossible to know without knowing how long each force acts. 
A) the 4.0-kg object 
B) the 1.0-kg object 
C) Both objects travel the same distance. 
D) It is impossible to know without knowing how long each force acts.

Question 16

Two objects,one of mass m and the other of mass 2m,are dropped from the top of a building.When they hit the ground

Accepted Answer

A) both of them will have the same kinetic energy. 
B) the heavier one will have twice the kinetic energy of the lighter one. 
C) the heavier one will have four times the kinetic energy of the lighter one. 
D) the heavier one will have   times the kinetic energy of the lighter one. 
A) both of them will have the same kinetic energy. 
B) the heavier one will have twice the kinetic energy of the lighter one. 
C) the heavier one will have four times the kinetic energy of the lighter one. 
D) the heavier one will have   times the kinetic energy of the lighter one.

Question 17

A 7.0-kg rock is subject to a variable force given by the equation
F(x)= 6.0 N - (2.0 N/m)x + (6.0 N/m2)x2
If the rock initially is at rest at the origin,find its speed when it has moved 9.0 m.

Accepted Answer

Question 18

A worker lifts a 20.0-kg bucket of concrete from the ground up to the top of a 20.0-m tall building.The bucket is initially at rest,but is traveling at 4.0 m/s when it reaches the top of the building.What is the minimum amount of work that the worker did in lifting the bucket?

Accepted Answer

A) 3.92 kJ 
B) 400 J 
C) 560 J 
D) 4.08 kJ 
E) 160 J 
A) 3.92 kJ 
B) 400 J 
C) 560 J 
D) 4.08 kJ 
E) 160 J

Question 19

Which of the graphs in the figure illustrates Hooke's Law?

Accepted Answer

A) Graph a 
B) Graph b 
C) Graph c 
D) graph d 
A) Graph a 
B) Graph b 
C) Graph c 
D) graph d

Question 20

An unusual spring has a restoring force of magnitude F = (2.00 N/m)x + (1.00 N/m2)x2,where x is the stretch of the spring from its equilibrium length.A 3.00-kg object is attached to this spring and released from rest after stretching the spring 1.50 m.If the object slides over a frictionless horizontal surface,how fast is it moving when the spring returns to its equilibrium length?

Accepted Answer

A) 2.06 m/s 
B) 4.33 m/s 
C) 3.27 m/s 
D) 5.48 m/s 
E) 1.50 m/s 
A) 2.06 m/s 
B) 4.33 m/s 
C) 3.27 m/s 
D) 5.48 m/s 
E) 1.50 m/s

Exam 9: Work and Kinetic Energy

The value of the dot product of two vectors depends on the particular coordinate system being used.

A car needs to generate in order to maintain a constant velocity of on a flat road.What is the magnitude of the total resistive force acting on the car (due to friction,air resistance,etc.)? (1 hp = 746 W)

The scalar product of vector = 3.00 + 2.00 and vector is 10.0.Which of the following vectors could be vector ?

A 3.00-kg ball swings rapidly in a complete vertical circle of radius 2.00 m by a light string that is fixed at one end.The ball moves so fast that the string is always taut and perpendicular to the velocity of the ball.As the ball swings from its lowest point to its highest point

Consider a plot of the displacement (x)as a function of the applied force (F)for an ideal elastic spring.The slope of the curve would be

A constant horizontal pull acts on a sled on a horizontal frictionless ice pond.The sled starts from rest.When the pull acts over a distance x,the sled acquires a speed v and a kinetic energy K.If the same pull instead acts over twice this distance:

A 1000.0 kg car is moving at If a truck has 18 times the kinetic energy of the car,how fast is the truck moving?

Two boys searching for buried treasure are standing underneath the same tree.One boy walks east and then north.The other boy walks west and then north.Find the scalar product of their net displacements from the tree.

A force F = bx3 acts in the x direction,where the value of b is 3.7 N/m3.How much work is done by this force in moving an object from to

A spring stretches by when a object is attached.What is the weight of a fish that would stretch the spring by

A force = 12 N - 10 N acts on an object.How much work does this force do as the object moves from the origin to the point

Which of the graphs in the figure represents a spring that gets less stiff the more it is stretched?

It requires 49 J of work to stretch an ideal very light spring from a length of 1.4 m to a length of 2.9 m.What is the value of the spring constant of this spring?

A 4.0-kg object is moving with speed 2.0 m/s.A 1.0-kg object is moving with speed 4.0 m/s.Both objects encounter the same constant braking force,and are brought to rest.Which object travels the greater distance before stopping?

Two objects,one of mass m and the other of mass 2m,are dropped from the top of a building.When they hit the ground

A 7.0-kg rock is subject to a variable force given by the equation F(x)= 6.0 N - (2.0 N/m)x + (6.0 N/m2)x2 If the rock initially is at rest at the origin,find its speed when it has moved 9.0 m.

A worker lifts a 20.0-kg bucket of concrete from the ground up to the top of a 20.0-m tall building.The bucket is initially at rest,but is traveling at 4.0 m/s when it reaches the top of the building.What is the minimum amount of work that the worker did in lifting the bucket?

Which of the graphs in the figure illustrates Hooke's Law?

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

A force F = bx³ acts in the x direction,where the value of b is 3.7 N/m³.How much work is done by this force in moving an object from to

A 7.0-kg rock is subject to a variable force given by the equation F(x)= 6.0 N - (2.0 N/m)x + (6.0 N/m²)x² If the rock initially is at rest at the origin,find its speed when it has moved 9.0 m.