Energy

Question 1

What is the definition of energy?

Answer 1

Energy is the ability to do work or cause change.

Question 2

What is the unit of energy?

Answer 2

The unit of energy is the Joule (J).

Question 3

True or False: Energy can be created and destroyed.

Answer 3

False: Energy cannot be created or destroyed, only transformed.

Question 4

Fill in the blank: The law of conservation of energy states that energy cannot be ______ or ______.

Answer 4

created; destroyed

Question 5

What is kinetic energy?

Answer 5

Kinetic energy is the energy of an object due to its motion.

Question 6

What is the formula for kinetic energy?

Answer 6

The formula for kinetic energy is KE = 1/2 mv², where m is mass and v is velocity.

Question 7

What type of energy is stored in an object due to its height?

Answer 7

Gravitational potential energy.

Question 8

What is the formula for gravitational potential energy?

Answer 8

The formula for gravitational potential energy is PE = mgh, where m is mass, g is gravitational field strength, and h is height.

Question 9

True or False: All forms of energy can be converted into other forms.

Answer 9

True.

Question 10

What is thermal energy?

Answer 10

Thermal energy is the energy that comes from the temperature of matter.

Question 11

What is the principle of energy transfer?

Answer 11

Energy transfer is the process of energy moving from one system to another.

Question 12

Multiple Choice: Which of the following is a renewable energy source? A) Coal B) Solar C) Natural Gas

Answer 12

B) Solar

Question 13

What is the difference between renewable and non-renewable energy?

Answer 13

Renewable energy can be replenished naturally, while non-renewable energy cannot be replaced once used.

Question 14

What is work done in physics?

Answer 14

Work done is the energy transferred when a force is applied to move an object over a distance.

Question 15

What is the formula for work done?

Answer 15

The formula for work done is W = Fd, where W is work, F is force, and d is distance.

Question 16

Fill in the blank: Power is the rate of ______ done.

Answer 16

work

Question 17

What is the unit of power?

Answer 17

The unit of power is the Watt (W).

Question 18

What is the formula for power?

Answer 18

The formula for power is P = W/t, where P is power, W is work done, and t is time.

Question 19

True or False: A machine that is 100% efficient does not waste any energy.

Answer 19

True.

Question 20

What is energy efficiency?

Answer 20

Energy efficiency is the ratio of useful energy output to the total energy input.

Question 21

What does a Sankey diagram represent?

Answer 21

A Sankey diagram represents the flow of energy, showing how much energy is input and how much is wasted.

Question 22

Multiple Choice: Which energy form is not renewable? A) Wind B) Solar C) Oil

Answer 22

C) Oil

Question 23

What is mechanical energy?

Answer 23

Mechanical energy is the sum of potential and kinetic energy in an object.

Question 24

Fill in the blank: The total mechanical energy of an object remains ______ in the absence of non-conservative forces.

Answer 24

constant

Question 25

What is chemical energy?

Answer 25

Chemical energy is the energy stored in the bonds of chemical compounds.

Question 26

What is the primary source of energy for the Earth?

Answer 26

The Sun.

Question 27

True or False: Nuclear energy is derived from the splitting or fusing of atomic nuclei.

Answer 27

True.

Question 28

Give 4 methods of energy transfer

Answer 28

Electric Heating Mechanic Radiation

Question 29

2 formulas for efficiency

Answer 29

Useful output energy transfer/ total input energy transfer Useful power output/ total power input

Question 30

How to work out specific heat capacity

Answer 30

Change in thermal energy (J) —————————————— mass (kg) x change in temperature (°C)

Question 31

Advantages of fossil fuels (coal, oil, gas)

Answer 31

Reliable, provides energy when needs Relatively cheap

Question 32

Disadvantages of fossil fuels

Answer 32

Releases CO2 affects climate change Non-renewable

Question 33

Advantages of switching from coal to gas

Answer 33

Generates less carbon Gas fired power stations turn on quicker

Question 34

Advantages of nuclear power

Answer 34

Does not release CO2 Reliable

Question 35

Disadvantages of Nuclear Power

Answer 35

Contains highly dangerous radioactive materials Extremely expensive

Question 36

Equation for elastic potential energy

Answer 36

E(J) = 0.5 x spring constant (n/m) x extension squared (m)

Question 37

Examples of chemical energy stores

Answer 37

Food Fuel Batteries

Question 38

4 different stores for energy

Answer 38

Kinetic energy Gravitational potential energy Thermal energy Chemical energy

Question 39

Give 4 examples of renewable energy resources

Answer 39

Wind energy Hydro-Electricity Tidal energy Solar energy

Question 40

Give an example of a non renewable energy resource

Answer 40

Fossil fuels (coal, oil, gas)

Question 41

3 advantages of fossil fuels

Answer 41

Reliable Can produce large amounts Cheap

Question 42

2 disadvantages of using renewable energy resources to generate power

Answer 42

Output determined by wind, speed etc so supply is uncertain

Question 43

Define momentum

Answer 43

Product of mass and velocity