Question 1

What is the SI unit for work?&#10;A)Newton&#10;B)Watt&#10;C)Kelvin&#10;D)Joule

Accepted Answer

The SI unit for work is the Joule (J). N (Newton) is the SI unit for force, W (Watt) is the SI unit for power, and K (Kelvin) is the SI unit for temperature.

Question 2

In the following equation, what does the x stand for? $$\text { elastic energy } = \frac { 1 } { 2 } k x ^ { 2 }$$&#10;A)deflection of spring from its unstretched position&#10;B)original length of unstretched spring&#10;C)spring force&#10;D)a generic unknown quantity

Accepted Answer

In the formula for elastic potential energy, $ x $ represents the deflection or displacement of the spring from its equilibrium or unstretched position.

Question 3

Work is found by multiplying force by what other physical quantity?&#10;A)distance&#10;B)mass&#10;C)power&#10;D)time

Accepted Answer

Work is calculated by multiplying the force applied to an object by the distance over which that force is applied, in the direction of the force.

Question 4

A ping pong ball and a bowling ball are moving with the same momentum.Which has the greater kinetic energy?&#10;A)The ping pong ball&#10;B)The bowling ball

Accepted Answer

The kinetic energy (KE) of an object is given by the formula KE = 1/2 mv^2, where m is the mass and v is the velocity of the object. For two objects with the same momentum (p = mv), the object with the smaller mass (like the ping pong ball) must have a higher velocity to have the same momentum as the object with a larger mass (like the bowling ball). Since kinetic energy depends on the square of the velocity, the ping pong ball, with its higher velocity, will have greater kinetic energy than the bowling ball.

Question 5

A stone is dropped from a bridge and allowed to free-fall downward.As it falls a certain distance its gravitational potential energy decreases by 1000J.By how much does the stone's
Kinetic energy increase? (Neglect air resistance.)

Accepted Answer

The answer of A stone is dropped from a bridge...

Question 6

While driving down the highway, your car must overcome the forces of friction and air
necessary to keep a car moving at a constant speed.While driving the car a distance of
100,000m, the car burns up 10.6 liters of gasoline.If gasoline contains 100,000,000 joules of
potential energy per liter, what is the efficiency of the car's engine?

Accepted Answer

The answer of While driving down the highway, your car...

Question 7

What is the SI unit for elastic energy?&#10;A)Newton&#10;B)Watt&#10;C)Kelvin&#10;D)Joule

Accepted Answer

The SI unit for elastic energy is Joule (J). Newton is the unit of force, Watt is the unit of power, and Kelvin is the unit of temperature. Therefore, option D is the correct answer as it represents the unit of energy.

Question 8

Energy is a fundamental dimension.

Accepted Answer

Energy is not a fundamental dimension itself; it is a derived quantity in physics, typically measured in terms of other fundamental dimensions such as mass, length, and time (e.g., joules in the SI system, where 1 joule = 1 kg·m²/s²). Fundamental dimensions include mass, length, time, electric current, temperature, amount of substance, and luminous intensity.

Question 9

Which produces the greater change in kinetic energy (assume that all of the work goes into kinetic energy):

Accepted Answer

The answer of Which produces the greater change in kinetic...

Question 10

In the absence if heat transfer, and assuming negligible losses and no work, conservation of mechanical energy states that the total mechanical energy of a system is&#10;A)increasing&#10;B)constant&#10;C)decreasing&#10;D)decreasing, then constant

Accepted Answer

In the absence of heat transfer, and assuming negligible losses and no work, the total mechanical energy of a system is conserved. This means it remains constant over time. Therefore, choice B, constant, is the correct answer.

Question 11

Which of the following requires the most work done by the brakes of a car?&#10;A)slowing down from 80 kmph to 55 kmph&#10;B)stopping from 55 kmph&#10;C)equal amounts of work for both

Accepted Answer

The answer of Which of the following requires the most...

Question 12

In the following equation, what does the k stand for? $$\text { elastic energy } = \frac { 1 } { 2 } k x ^ { 2 }$$&#10;A)kinetic energy&#10;B)spring constant&#10;C)elastic constant&#10;D)momentum

Accepted Answer

The answer of In the following equation, what does the...

Question 13

While using a push mower to mow your lawn, you notice that you push with a constant
horizontal force of 75N .How much work do you do while pushing the lawn mower a total
distance of

on level ground?

Accepted Answer

The answer of While using a push mower to mow...

Question 14

How much kinetic energy does a 3kg soccer ball have while moving at   toward your opponents' goal?

Accepted Answer

The answer of How much kinetic energy does a 3kg...

Question 15

What is the SI unit for kinetic energy?&#10;A)Newton&#10;B)Watt&#10;C)Kelvin&#10;D)Joule

Accepted Answer

The answer of What is the SI unit for kinetic...

Question 16

The sketch below shows a bowling ball return at a bowling alley.Estimate the required&#10;speed of the ball at point 1 so that it reaches point 2 with a speed of   .Point 2 is a height of

Accepted Answer

The answer of The sketch below shows a bowling ball...

Question 17

How much kinetic energy does a soccer ball have while moving at   toward your goal?

Accepted Answer

The answer of How much kinetic energy does a soccer...

Question 18

The change in gravitational potential energy is found by multiplying an object's change in elevation by its&#10;A)mass&#10;B)weight&#10;C)density&#10;D)height

Accepted Answer

The answer of The change in gravitational potential energy is...

Question 19

Power is a fundamental dimension.

Accepted Answer

The answer of Power is a fundamental dimension....

Question 20

What is the SI unit for gravitational potential energy?&#10;A)Newton&#10;B)Watt&#10;C)Kelvin&#10;D)Joule

Accepted Answer

The answer of What is the SI unit for gravitational...

Question 21

The largest source of electric power in the United States is&#10;A)solar&#10;B)natural gas&#10;C)nuclear&#10;D)coal&#10;E)hydroelectric

Accepted Answer

The answer of The largest source of electric power in...

Question 22

In general, efficiency is defined as&#10;A)output divided by input&#10;B)input divided by output&#10;C)output multiplied by input&#10;D)output minus input

Accepted Answer

The answer of In general, efficiency is defined as&#10;A)output divided...

Question 23

Power can be described as&#10;A)how hard you push&#10;B)how fast you push&#10;C)how far you push&#10;D)how long you push

Accepted Answer

The answer of Power can be described as&#10;A)how hard you...

Question 24

The time rate of doing work is called&#10;A)energy&#10;B)power&#10;C)force&#10;D)momentum

Accepted Answer

The answer of The time rate of doing work is...

Question 25

A team is more powerful than an individual because&#10;A)the team can do more work than the individual in the same amount of time&#10;B)the team can do the same amount of work as the individual, but in less time&#10;C)the team can do more work than the individual in less time&#10;D)All of the above.