Question 1

A spring with a spring constant of 2500 N/m. is stretched 4.00 cm. What is the work required to stretch the spring?

Accepted Answer

A) 4.00 J 
B) 0 J 
C) 1.00 J 
D) 3.00 J 
E) 2.00 J 
A) 4.00 J 
B) 0 J 
C) 1.00 J 
D) 3.00 J 
E) 2.00 J E

Question 2

A constant force acts on a moving object. The object makes a fixed magnitude of displacement in some direction. In general, in what direction is the displacement that will result in the object traveling with the least kinetic energy after the displacement occurs?

Accepted Answer

A) The same direction as the force 
B) The direction does not matter. 
C) In a direction perpendicular to the plane of the force and the velocity of the object 
D) The opposite direction as the force 
E) Any direction perpendicular to the force 
A) The same direction as the force 
B) The direction does not matter. 
C) In a direction perpendicular to the plane of the force and the velocity of the object 
D) The opposite direction as the force 
E) Any direction perpendicular to the force D

Question 3

The work done by a variable force in moving an object between two points is equal to the area under the force versus displacement curve between those two points.

Accepted Answer

A) True 
 B)False  True

Question 4

A 4.0 kg mass is moving with speed 2.0 m/s. A 1.0 kg mass 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 mass 
B) the 1.0 kg mass 
C) Both travel the same distance. 
D) Cannot be determined from the information given. 
A) the 4.0 kg mass 
B) the 1.0 kg mass 
C) Both travel the same distance. 
D) Cannot be determined from the information given.

Question 5

FIGURE 7-3  
-An object is under the influence of a force as represented by the force vs. position graph in Fig. 7-3. What is the work done as the object moves from 0 m to 4 m?

Accepted Answer

A) 20 J 
B) 30 J 
C) 0 J 
D) 40 J 
E) 70 J 
A) 20 J 
B) 30 J 
C) 0 J 
D) 40 J 
E) 70 J

Question 6

A 1.00-kg mass is attached to a spring hanging vertically and hangs at rest in the equilibrium position. The spring constant of the spring is 1.00 N/cm. The mass is pulled downward 2.00 cm and released. What is the speed of the mass when it is 1.00 cm above the point from which it was released?

Accepted Answer

A) 0.0443 m/s 
B) 1.67 m/s 
C) 0.0201 m/s 
D) 1.73 m/s 
E) The mass will not reach the height specified. 
A) 0.0443 m/s 
B) 1.67 m/s 
C) 0.0201 m/s 
D) 1.73 m/s 
E) The mass will not reach the height specified.

Question 7

FIGURE 7-3  
-An object is under the influence of a force as represented by the force vs. position graph in Fig. 7-3. What is the work done as the object moves from 6 m to 12 m?

Accepted Answer

A) 20 J 
B) 30 J 
C) 0 J 
D) 40 J 
E) 70 J 
A) 20 J 
B) 30 J 
C) 0 J 
D) 40 J 
E) 70 J

Question 8

A force is dependent on position and is given by ( 4.00 N/m)x   +(2.0 N/m2)xy   . An object begins at the origin. It first moves in a straight line to x = 1.00 m, y = 0.00 m. It then moves in a straight line to x = 1.00 m, y = 1.00 m. How much work is done on the object by the force during the motion described?

Accepted Answer

A) 3.00 J 
B) 0.00 J 
C) 2.50 J 
D) 1.50 J 
E) 2.00 J 
A) 3.00 J 
B) 0.00 J 
C) 2.50 J 
D) 1.50 J 
E) 2.00 J

Question 9

How much energy is needed to change the speed of a 1600 kg sport utility vehicle from 15.0 m/s to 40.0 m/s?

Accepted Answer

A) 1.10 MJ 
B) 10.0 kJ 
C) 20.0 kJ 
D) 40.0 kJ 
E) 0.960 MJ 
A) 1.10 MJ 
B) 10.0 kJ 
C) 20.0 kJ 
D) 40.0 kJ 
E) 0.960 MJ

Question 10

On a force vs. position graph, the area under the curve is a representation of

Accepted Answer

A) force. 
B) position. 
C) kinetic energy. 
D) potential energy. 
E) work. 
A) force. 
B) position. 
C) kinetic energy. 
D) potential energy. 
E) work.

Question 11

If the net work done on a certain object is zero, make a statement concerning its speed?

Accepted Answer

If the net work done on an obj

Question 12

Which of the following vectors is perpendicular to the vector 4.0   - 6.0   +2.0   ?

Accepted Answer

A) 2.0   -3.0
  +1.0
  
B) 3.0   -3.0
  +3.0
  
C) 1.0   -2.0
  +1.0
  
D) 1.0   +1.0
  +1.0
  
E) 2.0   +1.0
  
A) 2.0   -3.0
  +1.0
  
B) 3.0   -3.0
  +3.0
  
C) 1.0   -2.0
  +1.0
  
D) 1.0   +1.0
  +1.0
  
E) 2.0   +1.0

Question 13

A person applies a constant force on an object of mass 20 kg that causes the object to move horizontally at a constant speed of 0.20 m/s through a distance of 0.80 m. What is the work done on the object?

Accepted Answer

A) 160 J 
B) 10 J 
C) 16 J 
D) 0 J 
E) Cannot be determined without knowing the magnitude of the applied force. 
A) 160 J 
B) 10 J 
C) 16 J 
D) 0 J 
E) Cannot be determined without knowing the magnitude of the applied force.

Question 14

A person applies a constant force of 20 N to a rock of mass 1000 kg, for a total of 20 seconds. What is the work done by this person if the rock does not move at all by this applied force?

Accepted Answer

A) 1000 J 
B) 2000 J 
C) 20,000 J 
D) 0 J 
E) 400 J 
A) 1000 J 
B) 2000 J 
C) 20,000 J 
D) 0 J 
E) 400 J

Question 15

An object of mass 10.0 kg is initially at rest. A 100 N force causes it to move horizontally through a distance of 6.00 m. What is the change in the kinetic energy of this object?

Accepted Answer

A) 0 J 
B) 200 J 
C) 60.0 J 
D) 600 J 
E) 1000 J 
A) 0 J 
B) 200 J 
C) 60.0 J 
D) 600 J 
E) 1000 J

Question 16

If the net work done on an object is zero, then the object's kinetic energy

Accepted Answer

A) decreases. 
B) remains the same. 
C) increases. 
D) is zero. 
E) cannot be determined without knowing the object's mass. 
A) decreases. 
B) remains the same. 
C) increases. 
D) is zero. 
E) cannot be determined without knowing the object's mass.

Question 17

How large a force is required to accelerate a 1600 kg car from rest to a speed of 25 m/s in a distance of 200 m?

Accepted Answer

A) 1600 N 
B) 0 N 
C) 200 N 
D) 400 N 
E) 2500 N 
A) 1600 N 
B) 0 N 
C) 200 N 
D) 400 N 
E) 2500 N

Question 18

If you push twice as hard against a stationary brick wall, the amount of work you do

Accepted Answer

A) quadruples. 
B) doubles. 
C) is cut in half. 
D) remains constant but non-zero. 
E) remains constant at zero. 
A) quadruples. 
B) doubles. 
C) is cut in half. 
D) remains constant but non-zero. 
E) remains constant at zero.

Question 19

FIGURE 7-2   Three applied forces, FS1U1B11S1U1B0 = 20.0 N, FS1U1B12S1U1B0 = 40.0 N, and FS1U1B13S1U1B0 = 10.0 N act on an object with a mass of 2.00 kg which can move along an inclined plane as shown in the figure. The questions refer to the instant when the object has moved 0.600 m along the surface of the inclined plane in the upward direction. Neglect friction and use g = 10.0 m/sS1U1P12S1S1P0.
-Refer to Fig. 7-2. What is the amount of work done by force F2 as the object moves up the inclined plane?

Accepted Answer

A) 0 J 
B) 12.0 J 
C) 16.0 J 
D) 24.0 J 
E) 20.8 J 
A) 0 J 
B) 12.0 J 
C) 16.0 J 
D) 24.0 J 
E) 20.8 J

Question 20

FIGURE 7-1  
-Which of the graphs in Fig. 7-1 illustrates Hooke's Law?

Accepted Answer

A) graph a 
B) graph b 
C) graph c 
D) graph d 
E) none of these 
A) graph a 
B) graph b 
C) graph c 
D) graph d 
E) none of these

Exam 7: Work and Energy

A spring with a spring constant of 2500 N/m. is stretched 4.00 cm. What is the work required to stretch the spring?

A constant force acts on a moving object. The object makes a fixed magnitude of displacement in some direction. In general, in what direction is the displacement that will result in the object traveling with the least kinetic energy after the displacement occurs?

The work done by a variable force in moving an object between two points is equal to the area under the force versus displacement curve between those two points.

A 4.0 kg mass is moving with speed 2.0 m/s. A 1.0 kg mass 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?

FIGURE 7-3 -An object is under the influence of a force as represented by the force vs. position graph in Fig. 7-3. What is the work done as the object moves from 0 m to 4 m?

A 1.00-kg mass is attached to a spring hanging vertically and hangs at rest in the equilibrium position. The spring constant of the spring is 1.00 N/cm. The mass is pulled downward 2.00 cm and released. What is the speed of the mass when it is 1.00 cm above the point from which it was released?

FIGURE 7-3 -An object is under the influence of a force as represented by the force vs. position graph in Fig. 7-3. What is the work done as the object moves from 6 m to 12 m?

How much energy is needed to change the speed of a 1600 kg sport utility vehicle from 15.0 m/s to 40.0 m/s?

On a force vs. position graph, the area under the curve is a representation of

If the net work done on a certain object is zero, make a statement concerning its speed?

Which of the following vectors is perpendicular to the vector 4.0 - 6.0 +2.0 ?

A person applies a constant force on an object of mass 20 kg that causes the object to move horizontally at a constant speed of 0.20 m/s through a distance of 0.80 m. What is the work done on the object?

A person applies a constant force of 20 N to a rock of mass 1000 kg, for a total of 20 seconds. What is the work done by this person if the rock does not move at all by this applied force?

An object of mass 10.0 kg is initially at rest. A 100 N force causes it to move horizontally through a distance of 6.00 m. What is the change in the kinetic energy of this object?

If the net work done on an object is zero, then the object's kinetic energy

How large a force is required to accelerate a 1600 kg car from rest to a speed of 25 m/s in a distance of 200 m?

If you push twice as hard against a stationary brick wall, the amount of work you do

FIGURE 7-1 -Which of the graphs in Fig. 7-1 illustrates Hooke's Law?

Introduction, Measurement, Estimating

Describing Motion: Kinematics in One Dimension

Kinematics in Two or Three Dimensions; Vectors

Dynamics: Newtons Laws of Motion

Using Newtons Laws: Friction, Circular Motion, Drag Forces

Gravitation and Newtons6 Synthesis

Conservation of Energy

Linear Momentum

Rotational Motion

Angular Momentum; General Rotation

Static Equilibrium; Elasticity and Fracture

Fluids

Oscillations

Wave Motion

Sound

Temperature, Thermal Expansion, and the Ideal Gas Law

Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge and Electric Field

Gausss Law

Electric Potential

Capacitance, Dielectrics, Electric Energy Storage

Electric Currents and Resistance

Dc Circuits

Magnetism

Sources of Magnetic Field

Electromagnetic Induction and Faradays Law

Inductance, Electromagnetic Oscillations, and Ac Circuits

Maxwells Equations and Electromagnetic Waves

Light: Reflection and Refraction

Lenses and Optical Instruments

The Wave Nature of Light; Interference

Diffraction and Polarization

Special Theory of Relativity

Early Quantum Theory and Models of the Atom

Quantum Mechanics

Quantum Mechanics of Atoms

Molecules and Solids

Nuclear Physics and Radioactivity

Nuclear Energy: Efects and Uses of Radiation

Elementary Particle

Astrophysics and Cosmology

Filters