2018

• equation links to momentum, mass, and velocity

  Momentum=mass$\times$velocity
• A great spring constant means

  needs the greatest force to extend the spring the same amount
• zero error

  adjust back to 0
• describe the difference between transverse waves and longitudanal waves

  In a longitudanal wave,the vibrations are parallel to the direction of energy transfer in a transverse wave ,the virbrations are perpendiculer to the direction of eenerfy trasnfer.
• Q: Describe the relationships shown in Figure 9You should include factors that would affect the gradient of the lines.[6 marks]

  • Use of drugs, alcohol, tiredness and distractions would increase the thinking distance.
  • Thinking distance increases with speed.
  • Thinking distance is directly proportional to speed.
  • Poor brakes, poor tyres, wet/icy roads and mass would increase the braking distance.
  • Braking distance increases with speed.
  • Braking distance increases at an increasing (greater) rate with speed.
  • Braking distance is directly proportional to speed squared.
  • Stopping distance = thinking distance + braking distance.
  • Factors that increase thinking and/or braking distance would increase the gradient of stopping distance.
  • Stopping distance increases at an increasing (greater) rate with speed.
• When the brakes are used, the temperature of the brakes increases. Explain why. Use ideas about energy in your explanation.

  There is a decrease in kinetic energy of the car so this causes the thermal/internal energy store of the brakes to increase.
• Describe how the radio waves reaching the car aerial produce signals in the electrical circuit of the car radio.[3 marks]

  • The car aerial absorbs radio waves or energy.
  • Electrons in the aerial are made to vibrate.
  • This creates an alternating current in the aerial circuit.
  • The signal frequency is the same as the radio wave frequency.
• Explain how this electromagnet is able to pick up and move the blocks.[6 marks]

  Completing the circuit turns the electromagnet on.

  There is a current in the coil.

  A magnetic field is produced around the coil.

  The iron core becomes magnetised.

  The block is attracted to the electromagnet.

  Switching off the current switches off the electromagnet, releasing the block.
• Describe how another permanent magnet can be used to identify the blocks.[3 marks]

  Permanent magnet has no effect on the aluminium.

  Iron is attracted to the permanent magnet.

  Iron that is a magnet can be repelled by the permanent magnet.