P1

• suggest one advantage of the aircraft having fuel cells as well as the solar cells?

  Can fly at night
• What can an unmanned aircraft be used for?

  map the earths surface
• Why is no work done when a weight lifter lifts the weight and holds it above its head ?

  work is only done when a force makes an object move
• What does a turbine turn?

  a genorator
• what is the environmental impact of tides?

  destroys the habitat of wading birds in river estuaries
• what are the evironmental impacts of hydroelectricity?

  floods land used for farming or forestry
• Give one advantage of using a wind generator to charge a battery?

  wind may not always blow
• What is the unit for weight?

  newtons
• How do you calculate a skankey diagram?

  1 count number of squares

  2 do useful energy/ total energy
• Energy that is not usefully transformed by the fan heater is wasted as sound energy
• suggest why skiers should be mad aware of the benefits of wearing a helmet?


  so more are likely to wear one
• give a reason why doubling the diameter of the blades more than doubles the power output of a turbine?

  mass of air hitting blades more than doubles