Physics P8

• What is the thinking distance

  How far the car travels during the driver's reaction time
• What are the 2 factors that affect thinking distance

  The speed of the car and the reaction time
• What is the braking distance

  The distance taken to stop under the braking force
• What happens to the braking distance if the speed is doubled

  The braking distance increase by 4x
• What are the 3 main types of fossil fuel

  Crude oil, Natural gas and coal
• How are fossil fuels made

  Plants and animals remains are buried for millions of years.
• Why are biofuels seen as carbon neutral even though they produce carbon dioxide

  This is because they were collected from plants which collected CO2. There is no overall release in CO2
• Are biofuels renewable

  Yes if managed properly
• What are the 2 things we need to know about mains supply

  Alternating current of 230V and 50 Hz
• What colour is the neutral wire

  blue
• What colour is the earth wire

  green and yellow
• What colour is the live wire

  brown
• What does the live wire do

  Carries the current to the appliance. It has a p.d. of 230v
• What does the earth wire do

  The earth wire is a safety wire to stop the appliance becoming live. It has a p.d. of 0v
• What are the disadvantages of fuses

  They are only a one time use
• What is the order for the solar system

  Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune
• What are asteroids made out of

  rock and metal
• What are comets made out of

  Ice and dust
• What is the beginning of a star

  Cloud of dust and gas called the nebula. The force of gravity causes all of this dust and gas particles to come together forming a protostar
• What happens when the temperature of the protostar increase


  Hydrogen nuclei start to fuse together to form helium nuclei. This releases a lot of energy and the protostar has no become a main sequence star
• What are S-waves

  Secondary waves that move slowly and can't go through liquids. They are transverse