Physics

Question 1

Friction is:

A. insignificant in most real world applications

B. higher when the objects are in relative motion than when they are static with respect to each other

C. caused by motion

D. Caused by interaction between two surfaces in contact

Answer 1

D. Caused by interaction between two surfaces in contact

Question 2

In the equation F = ma

A. “a” refers to the acceleration, which has dimensions of length per unit of time ( e.g., feet per second.)

B. The equation clearly shows that an object at rest must have no forces applied to it.

C. “m” refers to mass, which is essentially the same as weight.

D. “F” refers to the total of all forces acting on the object.

Answer 2

D. “F” refers to the total of all forces acting on the object.

Question 3

what is the equation that describes the conservation of momentum, in the case where a collision of two objects occurs.

Answer 3

(m1v1)initial + (m2v2)initial = (m1v1)final + (m2v2)final

Question 4

Select the statement which is NOT true.

A. The friction between two surfaces is dependent on whether they are in motion or at rest with respect to each other.

B. The magnitude of the friction force is dependent on the surface area in contact.

C. The friction between two surfaces is dependent on the roughness of the surface.

D. The coefficient of friction between two materials is dependent on the surface area in contact.

Answer 4

D. The coefficient of friction between two materials is dependent on the surface area in contact.

Question 5

A force of 2,000 N is acting on a car causing it to accelerate at a constant rate of 2 m/sec2. Determine the mass of the car.

A. 2,000 kg

B. 1,000 kg.

C. 2,000 pounds

D. 1,000 pounds

Answer 5

B. 1,000 kg.

Question 6

The Law of Universal Gravitation states that:

A. All masses repel each other with a force that is inversely proportional to the distance between the masses.

B. All masses attract each other with a force inversely proportional to the product of their masses.

C. All masses attract each other with a force inversely proportional to the distance between the masses.

D. All masses repel each other with a force directly proportional to the product of their masses.

Answer 6

C. All masses attract each other with a force inversely proportional to the distance between the masses.

Question 7

Two objects are located 10 meters apart. The first object has a mass of 5.000 x 103 kg. The second object has a mass of 2.500 x 103 kg. Determine the gravitational force between these two objects.

A. 8.341 x 10-6 kg-m/sec2

B. 8.341 x 10-5 kg-m/sec2

C. 8.341 x 10-5 m3/kg-sec2

D. 8.341 x 10-6 m3/kg-sec2

Answer 7

A. 8.341 x 10-6 kg-m/sec2

Question 8

Assuming the crate below is at rest, which of the following statements about forces on the crate is false?

A. Any horizontal force applied must be less than the force caused by static friction, or the crate would move.

B. The crate is in force equilibrium.

C. No horizontal force can be applied, or the crate would not be at rest.

D. The normal force applied is equal to the force due to gravity.

Answer 8

C. No horizontal force can be applied, or the crate would not be at rest.

Question 9

Which of the following is not a term in the simplified energy balance?

A. Energy added

B. Wasted energy

C. Kinetic energy

D. Potential energy

Answer 9

B. Wasted energy

Question 10

Select all the true statements.

A. The mass of a body is the same, wherever the body is located. The weight of a body, however, depends upon the local acceleration due to gravity.

B. Weight is a function of mass only, and does not vary based on location.

C. Weight is a vector quantity.

D. Weight is a scalar quantity.

Answer 10

A. The mass of a body is the same, wherever the body is located. The weight of a body, however, depends upon the local acceleration due to gravity.

C. Weight is a vector quantity.

Question 11

Select all statements about the Law of Universal Gravitation that are true.

A. The law applies to every mass in the universe.

B. The force due to gravity is mutual.

C. The force due to gravity is directly proportional to the distance between the bodies.

D. The force due to gravity is attractive.

Answer 11

A. The law applies to every mass in the universe.

B. The force due to gravity is mutual.

D. The force due to gravity is attractive.

Question 12

Determine the number of hours in 46.5 days.

A. 1,016

B. 279

C. 2,790

D. 1,116

Answer 12

D. 1,116

Question 13

The ability to do work is known as:

A. power

B. kinetic energy

C. Energy

D. potential energy

Answer 13

C. Energy

Question 14

State Newton’s Second Law of Motion.

A. A particle with a force acting on it has an acceleration proportional to the magnitude of the force and in the direction of that force.

B. For every action, there is an equal but opposite reaction.

C. An object remains at rest (if originally at rest) or moves in a straight line with constant velocity if the net force on it is zero.

D. Motion of an object is determined by the size and shape of the object, not the mass of the object.

Answer 14

A. A particle with a force acting on it has an acceleration proportional to the magnitude of the force and in the direction of that force.

Question 15

The English system of units consists of what standard units?

Answer 15

• Foot • Pound • Second

Question 16

Convert 795 m to ft. Given 1m is equal to 3.281ft

Answer 16

(795 m)×(3.281 ft/m)=2.608×10^3 ft

Question 17

A man constantly exerts 50.0 lbf to move a crate 50 feet across a level floor. The move requires 10 seconds. What is the power expended by the man pushing the crate?

A. 0.450 horsepower

B. 2.50 x 103 foot-pounds force

C. 4.50 horsepower

D. 2.50 x 103 watts

Answer 17

A. 0.450 horsepower

Question 18

Calculate the momentum of a 3,500-pound car traveling at 55 miles per hour.

A. 621.133 kg-ft/sec.

B. 621,133 kg-ft/sec.

C. 3,106 kg-ft/sec.

D. 677,600 kg-ft/sec.

Answer 18

B. 621,133 kg-ft/sec.

Question 19

Calculate the potential energy of 2,000 kg of water which is being stored in a water tank 15 meters above ground level.

A. 30,000 Joules

B. 294,000 Joules

C. 30,000 Newtons

D. 294,000 Newtons

Answer 19

B. 294,000 Joules

Question 20

An object is moving at a constant velocity in a straight line. The net force acting on the object is zero. Which of the following statements regarding the object is true?

A. The object will continue to move in a straight line at a constant velocity regardless of the net force acting on the object.

B. The object will eventually come to a stop, regardless of the net force acting on the object.

C. The object will never come to a stop, regardless of the net force acting on the object.

D. As long as the net force acting on the object remains zero, the object will continue to move in a straight line at a constant velocity.

Answer 20

D. As long as the net force acting on the object remains zero, the object will continue to move in a straight line at a constant velocity.

Question 21

Which of the following is NOT an accurate definition of power?

A. Force times distance

B. Rate of doing work

C. Energy used per unit of time

D. Heat used per unit of time

Answer 21

A. Force times distance

Question 22

When an object is at rest,

A. no force is applied to the object.

B. the net force applied is not large enough to move the object.

C. gravitational force on the object is zero.

D. the net force, sum of all forces applied to the object, is zero.

Answer 22

D. the net force, sum of all forces applied to the object, is zero.

Question 23

The law of conservation of energy states:

A. Energy should not be wasted

B. The sum of potential energy and kinetic energy is always the same

C. Energy cannot be altered in form.

D. Energy cannot be created or destroyed

Answer 23

D. Energy cannot be created or destroyed

Question 24

An object with mass of 1.0 x 102 grams is traveling at 50 m/s when it strikes an object with mass of 10 kg, which is at rest. Assuming that the first object is at rest after the elastic collision, what is the velocity and direction of the second object?

A. 0.50 m/s, in the same direction that the first object was moving

B. 0.50 m/s, in the opposite direction that the first object was moving

C. 5.0 m/s, in the same direction that the first object was moving

D. 5.0 m/s in the opposite direction that the first object was moving

Answer 24

A. 0.50 m/s, in the same direction that the first object was moving

Question 25

Match the following dimensions to their equivalents. 1 3,280.8 feet 2 453,590 grams 3 0.017 hours 4 1.47 feet per second A. 1 mile per hour B. 1 lbm C. 1 minute D. 1 kilometer

Answer 25

1=D 2=B 3=C 4=A

Question 26

Assume the crate shown below is sitting on a level concrete floor. Which of the following correctly describes the forces applied to the crate? A. A horizontal friction force exists which always precisely matches any other horizontal force on the crate. B. A horizontal friction force is present at all times. C. The upward force is the normal force. The downward force is the weight of the crate. They are equal. D. There is no force on the crate. If there was, it would be in motion.

Answer 26

C. The upward force is the normal force. The downward force is the weight of the crate. They are equal.

Question 27

Convert 55 miles per hour into feet per second. A. 37 feet per second B 47.4 feet per second C. 80.67 feet per second D. 91 feet per second

Answer 27

C. 80.67 feet per second

Question 28

Weight is: A. a fundamental unit B. a function of mass and length C. a measurement that describes the force of gravity on the mass of an object. D. a constant, regardless of position with respect to other bodies

Answer 28

C. a measurement that describes the force of gravity on the mass of an object.

Question 29

Select all the true statements. A. Application of force always causes acceleration. B. Force is a vector quantity. C. When an object remains at rest, there is no force applied to the object. D. When an object remains at rest, the net force on the object is zero.

Answer 29

B. Force is a vector quantity. D. When an object remains at rest, the net force on the object is zero.

Question 30

Density is A. a measure of mass per unit volume and has dimensions of mass per length cubed. B. a measure of mass per unit volume and has units of mass per length squared. C. a measure of the gravitational force on a unit of mass. D. a measure of volume per unit mass and has units of length cubed per unit mass.

Answer 30

A. a measure of mass per unit volume and has dimensions of mass per length cubed.

Question 31

What are the 6 standard units of measurement in the SI system?

Answer 31

• Meter • Kilogram • Second • Centimeter • Gram • Second

Question 32

A race car is traveling at a constant velocity and goes one-quarter mile (1,320 feet) in 5 seconds. If the motor is generating a forward force of 1.89 x 103 lbf on the car, what is the power of the motor in hp? A. 1.00 x 103 watts B. 5.00 x 103 watts C. 9.07 x 102 horsepower D. 5.00 x 103 horsepower

Answer 32

C. 9.07 x 102 horsepower

Question 33

Calculate the number of minutes in 3.2 years. A. 164,000 B. 168,000 C. 1,640,000 D. 1,680,000

Answer 33

D. 1,680,000

Question 34

Match the following terms with the correct dimensions of measurement. 1 A measure of the change in velocity per unit time is centimeters per second per second (cm/s2) or feet per second per second (ft/s2) 2 The product of three lengths (e.g., length x width x depth for a rectangular solid) is (in3) or cubic meters (m3) 3 Mass of an object per unit volume is kilograms per cubic meter (kg/m3) or pounds per cubic foot (lbs/ft3) 4 Length per unit time is kilometers per hour (km/hr) or feet per second (ft/s) A. Density B. Acceleration C. Velocity D. Volume

Answer 34

1=B 2=D 3=A 4=C

Question 35

Select all the true statements. A. If the hanging object is at rest, the net forces applied to it must be zero. B. Cable T2 has no force applied to it. C. Cable T2 has a horizontal force pulling the hanging object to the left but no vertical force applied. D. Cable T1 has a vertical force to match the weight of the hanging object, and a horizontal force pulling the hanging object to the right.

Answer 35

A. If the hanging object is at rest, the net forces applied to it must be zero. C. Cable T2 has a horizontal force pulling the hanging object to the left but no vertical force applied. D. Cable T1 has a vertical force to match the weight of the hanging object, and a horizontal force pulling the hanging object to the right.

Question 36

The standard unit of mass in the cgs system is the A. milligram B. gram C. kilogram D. lbm

Answer 36

B. gram

Question 37

The fundamental dimensions are: A. time, force, and power B. mass, time, and force C. weight , length, and time D. mass, length, and time

Answer 37

D. mass, length, and time

Question 38

Which of the following is NOT a unit used to express power in mechanical systems? A. ft-lbf/s B. Horsepower C. Newtons D. Watts

Answer 38

C. Newtons

Question 39

Fluid forces are: A. generally insignificant B. compressive C. dominated by friction forces D. tensile

Answer 39

A. generally insignificant

Question 40

Which of the following statements describes the conservation of momentum? A. The sum of a system's initial momentum is equal to the sum of a system's final momentum. B. The force acting on an object is a product of the object's mass and its acceleration. C. For every action, there is an equal and direct reaction. D. The sum of a system's initial momentum is greater than the sum of a system’s final momentum.

Answer 40

A. The sum of a system's initial momentum is equal to the sum of a system's final momentum.

Question 41

Which of the following is not a real force A. centripetal B. tensile force C. centrifugal D. friction

Answer 41

C. centrifugal

Question 42

Determine the number of seconds in 8 hours. A. 2,480 B. 24,800 C. 2,880 D. 28,800

Answer 42

D. 28,800

Question 43

The standard unit of measure for time is the A. second B. minute C. hour D. year

Answer 43

A. second

Question 44

Select all statements about the friction force that are true. A. The direction of the friction force is opposite the direction of motion. B. The coefficient of kinetic friction between two surfaces is greater than the coefficient of static friction for the same two surfaces. C. Friction force is proportional to the normal force. D. When an object is not moving, the friction force is zero.

Answer 44

A. The direction of the friction force is opposite the direction of motion. C. Friction force is proportional to the normal force.

Question 45

Calculate the kinetic energy of a 500-kg car traveling at 8.00 x 101 km/hr. A. 1.23 x 105 N B. 1.23 x 105 J C. 3.20 x 106 J D. 3.20 x 106 N

Answer 45

B. 1.23 x 105 J

Question 46

A free-body diagram must contain: A. the object of interest and all forces acting on the object. B. a detailed description of the object in question. C. any other information of interest about the object, whether pertinent to the problem or not. D. all physical connections to the object.

Answer 46

A. the object of interest and all forces acting on the object.

Question 47

Derived measurements are A. combinations of the fundamental dimensions which are useful in characterizing the physical property or behavior of objects. B. conversion factors to relate the English system to the mks system. C. always required to have all three fundamental dimensions. D. conversion factors to relate the English system to the cgs system.

Answer 47

A. combinations of the fundamental dimensions which are useful in characterizing the physical property or behavior of objects.

Question 48

The measurement system most used in the United States when dealing with physics is: A. foot - pound - second B. mks C. cgs D. foot - pound - minute

Answer 48

A. foot - pound - second

Question 49

Convert 1 cubic foot per second into liters per minute. A. 55,742 liters per minute B. 169,900,000 liters per minute C. 1,699 liters per minute D. 28,317 liters per minute

Answer 49

C. 1,699 liters per minute

Question 50

Potential energy is: A. energy due to position or elevation. B. the capability of an object or substance to do work if utilized C. a possible future energy source D. energy that could be applied to perform work

Answer 50

A. energy due to position or elevation.

Question 51

Which of the following is NOT a fundamental dimension? A. Weight B. Length C. Mass D. Time

Answer 51

A. Weight

Question 52

Two railroad cars have masses of m1 = 1,500 kg and m2 = 1,250 kg. The first car is moving at a velocity of 7.0 m/s and the second car is moving at a velocity of 5.0 m/s. The first car overtakes the second car and couples with it. Calculate the final velocity of the two cars. A. 6.1 m/s B. 5.9 m/s C. 6.2 m/s D. 6.0 m/s

Answer 52

A. 6.1 m/s

Question 53

# Define momentum. A. A measure of the motion of a moving body. It is the result of the product of the body's mass and the velocity at which it is moving. B. A measure of the velocity of a moving body. C. A measure of the mass of a moving body. D. A measure of the density of a moving body.

Answer 53

A. A measure of the motion of a moving body. It is the result of the product of the body's mass and the velocity at which it is moving.

Question 54

Two moving objects collide. The first object was traveling at 5.00 m/s and has a mass of 5 kg. The second object has a mass of 2 kg. At what velocity and direction must the second object have been traveling, for the combined objects to be at rest after the collision? A. 25.0 m/s , in the same direction as the first object. B. 12.5 m/s, perpendicular to the first object. C. 25.0 m/sec, in the opposite direction of the first object. D. 12.5 m/s, in the opposite direction of the first object.

Answer 54

D. 12.5 m/s, in the opposite direction of the first object.

Question 55

Select all the true statements. A. Momentum is conserved in all collisions. B. Momentum is conserved in elastic collisions, but not in inelastic collisions. C. Momentum of an object may be changed by applying force to the object. D. Momentum is a vector quantity.

Answer 55

A. Momentum is conserved in all collisions. C. Momentum of an object may be changed by applying force to the object. D. Momentum is a vector quantity.

Question 56

A boy rolls a ball with a steady force of 1.0 lbf, giving the ball a constant velocity of 5 ft/s. What is the power expended by the boy in rolling the ball? A. 9.0 x 10-3 watts B. 9.0 x 10-2 watts C. 9.0 x 10-3 horsepower D. 9.0 x 10-2 horsepower

Answer 56

C. 9.0 x 10-3 horsepower

Question 57

What are the three fundamental measurements:

Answer 57

* Length: distance between two points * Mass: amount of material in an object * Time: duration between two instants

Question 58

A force of 5.00 x 101 N is applied to an object through a distance of 16 feet. Calculate the amount of work done. A. 8.00 x 102 J B. 8.00 x 102 ft-lbf C. 2.44 x 102 ft-lbf D. 2.44 x 102 J

Answer 58

D. 2.44 x 102 J