# Physics S2

Cards for S2 Physics Exam

?
• Created by: Magnus
• Created on: 08-05-12 18:41

## Heat

Objects become hot when the atoms in the object vibrate.

1 of 8

## Low temperatures and high temperatures

The atoms in colder objects vibrate slower than those in hotter objects.

Bonus extra: Absolute zero ( 0 degrees Kelvin ) is the point at which molecular motion is at a minimum (try saying that 10 times fast :P)

2 of 8

## Heat energy

Bigger objects generally have more heat energy i.e although a sparkler is hotter than an iceberg, since the iceberg is so much bigger it has more heat energy.

3 of 8

## Moving heat

A cup of coffee will cool down because it's giving out its heat energy to the surroundings. There are 3 methods of heat transfer:

Conduction: The heat energy is passed around the object from atoms bumping into each other. Most metals are good conductors.

Convection: This type of heat transfer only occurs in fluids (gases or liquids). It is when a fluid moves around and carries heat with it. Some of the fluid gets heated and rises (because it is less dense). At the top, the fluid will cool and fall back down again. Key words: convection current

Radiation: Using this method, heat can travel through a vacuum.The energy is carried in infrared waves.

4 of 8

## Refraction Keywords Galore

Refraction: The bending of light through different materials

Opaque: Lets no light through

Translucent: Lets some light through

Transparent: Lets all light through

Incident ray: The beam of light that is arriving in a prism

Angle of incidence: The angular distance of the incident ray from the normal

Normal: A line straight through the middle of the prism

Refracted ray: The beam of light that comes out of a prism

Angle of Refraction: The angular distance of the refracted ray from the normal.

5 of 8

## Light + Lenses

Convex lenses make light converge

Concave lenses make light diverge

White light splits into different colours when it travels through a prism.

Remember ROY G BIV

Red

Orange

Yellow

Green

Blue

Indigo

Violet

6 of 8

## Sound and Hearing

• Sound travels as waves formed when something vibrates
• Sound needs a medium to travel through!
7 of 8

## Waves

• High pitched noises are high frequency
• Low pitched noises are low frequency
• Loud noises have high amplitude
• Quiet noises have low amplitude
• Frequency is measured in Hertz
• Human hearing is from around 20Hz to 20kHz.
• Amplitude is measured in decibels (dB)
• Sounds above 80dB can damage your hearing.
8 of 8