Making Machines

KEY IDEAS

  • Machines make work seem easier to do
  • Energy is needed to make machines work
  • Energy is transferred from its source to where it is needed
  • Levers, ramps, pulleys and gears make tasks easier by transferring energy to where it is needed

EXAMPLE QUESTIONS

  • What do you think a machine is?
  • What different machines do you know?
  • What makes machines ‘go’?

MACHINES MAKE TASKS EASIER

  • Machines are devices that are designed and used by people to make jobs easier.
  • Some examples of machines are lawnmowers, sewing machines and computers.

MACHINES NEED ENERGY TO MAKE THEM OPERATE

  • Energy is essential for machines. Some simple machines get the energy they need from human muscles.
  • Some require other sources of energy, such as electricity , heat, chemical or nuclear power, or the movement of wind or water.
  • Some machines keep replaceable or rechargeable energy stored inside them (batteries or wind-up springs, for example); others get heat energy from fuels, such as oil, coal and wood.
  • Other machines are attached to centrally supplied energy sources (electrical power lines and gas mains).
  • All machines need a source of energy to make them operate.

MACHINES INVOLVE THE TRANSFER OF ENERGY

  • All machines take energy from one source and transfer it to another.
  • A pair of scissors takes energy from our hands and transfers it to the cutting blades.
  • A car takes the stored energy in petrol and transfers it into heat in the engine and then from the engine to the wheels.