Energy And Heat

Question 0

How do humans get their energy?

Answer 0

Humans get all their energy from the food that we eat

Question 1

What is the definition of Energy?

Answer 1

The Ability To Do Work

Question 2

What does our food consist of?

Answer 2

Our food consists of plants and animals which get their energy from the sun and nutrients from the ground

Question 3

What are coal, oil and gas grouped together as?

Answer 3

They are grouped together as Fossil Fuels

Question 4

How are fossil fuels created?

Answer 4

Living things, plants and animals, die and decompose. They are covered by tons of sand and over thousands of years become fossil fuels

Question 5

What is another name for fossil fuels?

Answer 5

We can call fossil fuels a Non-Renewable source of energy

Question 6

What are the two main forms of energy?

Answer 6

Potential Energy and Kinetic Energy

Question 7

What is potential energy known as?

Answer 7

It is known as stored energy which a body has due to its position

Question 8

What are 3 alternatives that man can use to replace fossil fuels?

Answer 8

Solar Power, Wind Power and Hydro-Electric Power Energy

Question 9

Where is South Africa’s only nuclear power station?

Answer 9

There is a nuclear plant at Koeberg in Cape Town

Question 10

What are 2 advantages of nuclear energy?

Answer 10

No air pollution is produced

There is less waste products than in coal power station

Question 11

What are 3 disadvantages of nuclear energy?

Answer 11

If there is an accident radio-active substances can be released

The waste products are harmful and remain dangerous for thousands of years

It is very expensive to buil da nuclear plant

Question 12

List 5 different forms of energy

Answer 12

Gravitational Energy
Elastic Energy
Sound Energy
Light Energy
Mechanical Energy

Question 13

What is Kinetic Energy?

Answer 13

It is the energy possessed by a moving body

Question 14

What is the law of conservation of energy?

Answer 14

Energy can never be created or destroyed it can only be converted from one type to another

Question 15

Give 2 examples of good conductors of heat?

Answer 15

Metal and Glass

Question 16

Give 3 examples of poor conductors?

Answer 16

Plastic, Wood and Rubber

Question 17

How does convection of heat energy happen?

Answer 17

The heated particles expand, become less dense and rise, as they rise they spread out, they then cool, become more dense and sink to be heated again

Question 18

How does radiation of heat energy happen?

Answer 18

Heat from the sun reaches us after traveling through space where there is a vacuum. There are no particles to pass the heat energy by convection or conduction. The energy is transferred by radiation

Question 19

Give 5 changes that energy can cause to a substance

Answer 19

Colour
Size
Shape
Phase/State
Temperature

Question 20

What are the 3 ways in which heat can be transferred?

Answer 20

Solid: Conduction
Liquid: Convection
Gas: Convection/Radiation

Question 21

Where are 5 places in the house where heat is lost in winter?

Answer 21

The Roof
Ventilation
Walls
Windows
Floors

Question 22

Where are the 4 places in a house where heat is gained in summer?

Answer 22

The Roof
Ventilation
Walls
Windows