Unit 1 - Defintions

Question 1

Efficiency

Answer 1

The proportion of useful energy compared to the total input energy

Question 2

Evaporation

Answer 2

The cooling effect when particles of a liquid change to the gas state

Question 3

Specific heat capacity

Answer 3

The amount of energy needed to heat 1kg of material by 1 degree Celsius

Question 4

Echo

Answer 4

A reflected sound wave

Question 5

Convection

Answer 5

Particles in a liquid or gas move further apart as they gain energy. The liquid or gas becomes less dense (they expand). The particles/liquid/gas rises.

Question 6

The Doppler Effect

Answer 6

The change in wavelength of waves from a source moving compared to the observer

Question 7

U-values

Answer 7

A measure of how good an insulator a material is

Question 8

Redshift

Answer 8

The increase in wavelength of light from a distant galaxy

Question 9

Geothermal energy

Answer 9

Energy from hot rocks in the ground

Question 10

Normal

Answer 10

An imaginary line perpendicular to the boundary between two substances

Question 11

Virtual image

Answer 11

An image formed behind a mirror, where real light rays do not meet

Question 12

Diffraction

Answer 12

The spreading out of waves through a gap

Question 13

Conduction

Answer 13

The transfer of heat through free electrons colliding with metal ions