5 - Work, energy and power

Question 1

What is kinetic energy?

Answer 1

Energy due to motion of an object with mass.

Question 2

What is Gravitational Potential Energy?

Answer 2

Energy of an object due to its position in a gravitational field.

Question 3

What is Chemical Energy?

Answer 3

Energy contained within the chemical bonds between atoms - it can be released when atoms are rearranged.

Question 4

What is Elastic Potential Energy?

Answer 4

Energy stored in an object as a result of reversible change in its shape.

Question 5

What is Electrical Potential Energy?

Answer 5

Energy of electrical charges due to their position in an electric field.

Question 6

What is Nuclear Energy?

Answer 6

Energy within the nuclei of atoms - it can be released when the particles within the nucleus are rearranged.

Question 7

What is Radiant (or electromagnetic) energy?

Answer 7

Energy associated with all electromagnetic waves, stored within the oscillating electric and magnetic fields

Question 8

What is Sound Energy?

Answer 8

Energy of mechanical waves due to the movement of atoms

Question 9

What is Thermal energy?

Answer 9

Energy which arises when the temperature of a substance increases and causes its atoms to move faster and collide.

Question 10

Give two examples of kinetic energy.

Answer 10

Moving car

Moving atoms

Question 11

Give two examples of gravitational potential energy.

Answer 11

Child at the top of a slide

Water held in clouds

Question 12

Give two examples of chemical energy.

Answer 12

Energy stored within a chemical cell

Energy stored in petrol and released when it is burnt

Question 13

Give two examples of elastic potential energy.

Answer 13

A stretched guitar string

A squashed spring

Question 14

Give two examples of electrical potential energy.

Answer 14

Electrical charges in a thundercloud

Static charge on a charged balloon

Question 15

Give two examples of nuclear energy.

Answer 15

Energy from fusion processes in the Sun

Energy from nuclear fission reactors

Question 16

Give two examples of radiant energy.

Answer 16

Energy from the hot sun

Energy from an LED

Question 17

Give two examples of sound energy.

Answer 17

Energy emitted when you clap

Output energy from your headphones

Question 18

Give an example of something with a lot of thermal energy.

Answer 18

A hot cup of tea.

Question 19

What is the unit for work done?

Answer 19

The Joule

Question 20

What is energy?

Answer 20

The capacity for doing work.

Question 21

What is the principle of conservation of energy?

Answer 21

The total energy for a closed system must remain constant.

Energy can neither be created or destroyed, only transferred from one form to another.

Question 22

What is work done?

Answer 22

Energy that is transferred by a force.

Question 23

What does the term “potential” mean in physics?”

Answer 23

Hidden or stored.

Question 24

What is the equation for kinetic energy?

Answer 24

KE = ½ m * v^2

Question 25

What is the equation for gravitational potential energy?

Answer 25

GPE = m * g * h

Question 26

Define power.

Answer 26

Power is the rate of transfer of energy.

Question 27

WHAT is the unit of power..?

Answer 27

Watts

Question 28

How do you calculate the power of a moving object?

Answer 28

Force x velocity

Question 29

What is efficiency?

Answer 29

The proportion of useful energy output to the total energy input in a system.

(useful/total x 100)