Question 1

In the U.S.customary system of units, the unit for kinetic energy is

Accepted Answer

Kinetic energy in the U.S. customary system is measured in foot-pounds (lbf.ft), which is a unit of work or energy.

Question 2

What is the SI unit for gravitational potential energy?

Accepted Answer

Gravitational potential energy is measured in Joules (J) in the SI unit system.

Question 3

An object having a mass m and moving with a speed V has a kinetic energy, which is equal to

Accepted Answer

The formula for kinetic energy is KE = ½ mv2, where m is mass and v is velocity. Therefore, the correct option is C) ½ mV2.

Question 4

Which of the following requires the most work done by the brakes of a car?

Accepted Answer

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

Question 5

A ping pong ball and a bowling ball are moving with the same momentum.Which has the greater kinetic energy?

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 6

How much kinetic energy does a 200 g soccer ball have while moving at  toward your opponents' goal?

Accepted Answer

The answer of How much kinetic energy does a 200...

Question 7

Mechanical work is performed when a force moves an object through a distance.

Accepted Answer

This is the definition of mechanical work according to physics.

Question 8

What is the SI unit for elastic energy?

Accepted Answer

The standard unit of energy is joule (J) in the SI system. Elastic energy is a type of potential energy, which is also measured in joules. Therefore, the SI unit for elastic energy is joules (J).

Question 9

If you were to push a lawn mower with a constant horizontal force of 20 N.How much work do you do while pushing the lawn mower a total distance of 100 m on level ground?

Accepted Answer

The answer of If you were to push a lawn...

Question 10

Calculate the energy required to lift an elevator and its occupants with a mass of 1000 kg through a vertical distance of 5 m.

Accepted Answer

The energy required is calculated using the formula for gravitational potential energy: E = mgh, where m = 1000 kg, g = 9.8 m/s², and h = 5 m. So, E = 1000 * 9.8 * 5 = 49000 J.

Question 11

What is the SI unit for work?

Accepted Answer

The SI unit for work is Joules, which is defined as the amount of energy transferred when a force of one Newton is applied over a distance of one meter. Choice A (Newtons) is the unit of force, choice B (Watts) is the unit of power, and choice C (Kelvins) is the unit of temperature.

Question 12

In the following equation, what does the k stand for? elastic energy

Accepted Answer

In the equation for elastic energy, the k stands for spring constant, which is a measure of the stiffness of a spring or a material. The other answer choices (kinetic energy, modulus of elasticity, momentum) do not have direct relationships with elastic energy.

Question 13

Work is found by multiplying force by what other physical quantity?

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 14

When work is done on or against an object, it changes the kinetic energy of the object

Accepted Answer

Work changes the energy of an object, which can either increase or decrease its kinetic energy.

Question 15

A stone is dropped from a bridge and allowed to free-fall downward.As it falls a certain distance its gravitational potential energy decreases by1000 J.By how much does the stone's kinetic energy increase? (Neglect air resistance).

Accepted Answer

In the absence of air resistance, the decrease in gravitational potential energy is equal to the increase in kinetic energy. Therefore, the stone's kinetic energy increases by 1000 J.

Question 16

The change in gravitational potential energy is found by multiplying an object's change in elevation by its

Accepted Answer

The change in gravitational potential energy is calculated by multiplying the object's weight (mass * acceleration due to gravity) by its change in height. Weight is the force due to gravity, which directly influences gravitational potential energy.

Question 17

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 18

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

Accepted Answer

The work done, which equals the change in kinetic energy, is calculated as force times distance. For option A, the work done is 10 N * 5 m = 50 J, which is greater than the work done in the other options.

Question 19

Power is a derived dimension.

Accepted Answer

Power is a derived dimension as it is calculated by dividing the work or energy by time, and its unit is watts (W) or joules per second (J/s).

Question 20

What is the SI unit for gravitational potential energy?

Accepted Answer

The SI unit for gravitational potential energy is Joules (J).

Quiz 13: Energy and Power

In the U.S.customary system of units, the unit for kinetic energy is

What is the SI unit for gravitational potential energy?

An object having a mass m and moving with a speed V has a kinetic energy, which is equal to

Which of the following requires the most work done by the brakes of a car?

A ping pong ball and a bowling ball are moving with the same momentum.Which has the greater kinetic energy?

How much kinetic energy does a 200 g soccer ball have while moving at toward your opponents' goal?

Mechanical work is performed when a force moves an object through a distance.

What is the SI unit for elastic energy?

If you were to push a lawn mower with a constant horizontal force of 20 N.How much work do you do while pushing the lawn mower a total distance of 100 m on level ground?

Calculate the energy required to lift an elevator and its occupants with a mass of 1000 kg through a vertical distance of 5 m.

What is the SI unit for work?

In the following equation, what does the k stand for? elastic energy

Work is found by multiplying force by what other physical quantity?

When work is done on or against an object, it changes the kinetic energy of the object

A stone is dropped from a bridge and allowed to free-fall downward.As it falls a certain distance its gravitational potential energy decreases by1000 J.By how much does the stone's kinetic energy increase? (Neglect air resistance) .

The change in gravitational potential energy is found by multiplying an object's change in elevation by its

Energy is a fundamental dimension.

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

Power is a derived dimension.

What is the SI unit for gravitational potential energy?