P5

• Investigating mass and force:

  • trolley practical
  • light gates
  • pulley
  • Magnets
  • Record acceleration with the light gates as more magnets are added
• Stopping distance = Thinking Distance + Braking distance
• Thinking distance is affected by:

  • your speed - the faster youre going the further you'll travel during the time you take to react
  • your reaction time - The longer your reaction time, The longer your thinking distance
• Braking distance is affected by

  • your speed
  • the weather or road surface - it its slippery it can cause less friction between the friction between the tyres and the road, which can cause the tyres to skid
  • The condition of your tires
  • How good your brakes are
• Braking relies on Friction between the brakes and wheels

  • when the brake pedal is pushed, this causes brake pads to be pressed onto the urees. This causes friction, which causes work to be done. the work done between the brakes and the wheels causes the brakes to heat up
  • The faster a venice is going the more work that needs to be done to stop It
  • A larger braking force means a large deceleration. this can be dangerous as it could cause the brakes to overheat or the venice to Skid
• Measure reactivity time:

  • ruler drop test
  • catch the ruler , the longer the distance the longer the reaction time
• momentum:

  Momentum = mass x velocity

  momentum before is the same as momentum after a collision