Energy

Question 1

What is the equation for energy efficiency?

Answer 1

useful energy/total energy x100

Question 2

Define renewable energy sources

Answer 2

Resources that are able to last indefinitely without any reduction in supply. Replaced through natural processes quicker than they are being used.

Question 3

What is nuclear energy? How does it work?

Answer 3

Using Uranium to produce electricity. Works by a neutron striking the uranium, splitting it which releases heat, heats water, steam, turbine, generator, electricity

Question 4

Define nonrenewable energy sources

Answer 4

Exists only in limited deposits across earth. Cannot be replaced at a level equal to or greater than the rate at which it is being used.

Question 5

What is biomass fuel?

Answer 5

Energy derived from material produced by living things

Question 6

Define kinetic energy

Answer 6

Energy associated with the movement of an object or particles.

Question 7

Define potential energy

Answer 7

‘Stored’ energy that can be released to perform work

Question 8

Define chemical energy

Answer 8

Potential energy stored in the bonds of chemical compounds

Question 9

What is energy?

Answer 9

The capacity to perform work

Question 10

How do you calculate useful energy?

Answer 10

1. The amount of work done

2. Energy input - energy lost

Question 11

Equation for energy? (joules)

Answer 11

Power (watts) x time (seconds)

Question 12

What is a nonrenewable, non-fossil fuel energy source?

Answer 12

Nuclear

Question 13

What is the equation for power? (watts)

Answer 13

Energy (joules)/time(seconds)

Question 14

What are the two different categories of renewable energy?

Answer 14

1. Those that are infinite and available irrespective of rate of use (wind)
2. Those that are renewable as long as their rate does not exceed their rate of replenishment (eg wood)

Question 15

What is a fuel?

Answer 15

A substance that contains chemical energy that is released when oxidised

Question 16

What is an energy source?

Answer 16

Naturally occurring fuels or sources of energy that can be converted into useful forms

Question 17

Define endothermic and exothermic reactions

Answer 17

Exo - releases energy

Endo - takes up energy

Question 18

What is power?

Answer 18

The amount of energy used or available over a given period of time

Question 19

What is a joule?

Answer 19

A unit of energy that can:

1. Heat up 1cm^3 of water by 0.25*C
2. Lift 100g mass by 1cm

Question 20

What is temperature

Answer 20

The average kinetic energy of molecules within a material or substance.

Question 21

Second law of thermodynamics?

Answer 21

No conversion of energy is 100%. Some energy is always degraded to a less usable energy form (usually heat)

Question 22

First law of thermodynamics?

Answer 22

Energy is neither created nor destroyed, merely changed from one form to another

Question 23

One kilojoule is how many times bigger than a joule?

Answer 23

1000

Question 24

Difference between black and brown coal? Which is cleaner?

Answer 24

Black is more efficient bc brown coal has higher water content

Question 25

What is a fossil fuel?

Answer 25

A fuel formed from organic matter put under large amounts of heat and pressure due to being buried under sediment or rocks for long geological periods of time.

Question 26

Define combustion

Answer 26

The reaction of a fuel with oxygen resulting in the release of energy

Question 27

Define mechanical energy

Answer 27

The amount of energy possessed by an object due to it’s movement and it’s position. Conversion of potential energy into other forms of energy involving movement

Question 28

What is a watt?

Answer 28

One joule per second