B2: Greenhouse effect

Physics 11

Degraded energy

Energy transferred to the surroundings that is no longer available to perform useful work

Non-renewable

Sources of energy that can be used up and eventually run out.

Intensity

Power per unit area. For waves it is proportional to the square of its amplitude (I ∝ A^2)

Emissivity

The ratio of power radiated per unit area by an object to the power radiated per unit area by an black body at the same temperature

Albedo

The fraction of radiation received by a planets surface that is reflected back into space

Solar constant

The amount if solar energy that falls per second on an area of 1 m^2 above the Earth’s atmosphere at right angles to the Sun’s rays.

Greenhouse effect

Short wave radiation is absorbed and re-emitted by the Earth’s surface as infra-red and then absorbed by greenhouse gases in the atmosphere (and re-radiated in all

directions)

Emmisivity

Albedo