8. The specific latent heat of fusion of a substance is the amount of heat required to change 1 kg of the substance from a solid to a liquid without a change in temperature.
9. The specific latent heat of vaporisation of a substance is the amount of heat required to change 1 kg of the substance from a liquid to a gas without a change in temperature.
10. Conduction is the way in which heat travels through a substance with no overall movement of the substance.
11. Convection is the transfer of heat through a fluid by means of circulating fluid. 12. Radiation is the transfer of heat by means of electromagnetic waves.
13. Solar Irradiance is the average amount of the Sun’s energy falling per second perpendicularly on 1 metre squared of the Earth’s atmosphere.
Waves, Sound and Light
Waves 1. A wave is a disturbance that carries energy from one place to another.
2. Transverse waves are waves in which the direction of vibration is perpendicular to the propagation of the wave.
3. Longitudinal waves are waves in which the direction of vibration is parallel to the propagation of the wave.
4. Mechanical waves are the vibration of particles.
5. Electromagnetic waves are the disturbance/vibration of electric and magnetic (electromagnetic) fields.
6. Periodic travelling waves are a regularly repeating cycle that appears to move in the direction of propagation of the wave.
7. A crest is the highest point of a transverse wave. 8. A trough is the lowest point of a transverse wave. 9. An oscillation (or cycle) is one complete vibration of the source.
10. Wavelength is the distance from a point on a wave to the corresponding point on an adjacent wave.
11. Frequency is the number of waves passing a point per second. 12. Amplitude is the maximum distance from the undisturbed position. 13. The velocity of a wave is the product of wavelength and frequency. 14. Reflection is when a wave bounces off an object in its path.
15. Refraction is the changing of direction of a wave when it goes from one medium to another.
16. Diffraction is the spreading out of a wave into the space beyond a barrier. 17. Interference is the addition of two or more waves, forming a single resultant wave.
18. Constructive interference is when two or more waves combine, resulting in a single wave of greater amplitude than source waves.
