1. A magnetic field can change the direction of motion of a charged particle yet in doing so it has done no work on the particle. Why? Give another example of a force causing an object to change direction without doing any work on it.
2. Explain why it takes more fuel for a spacecraft to travel to the Moon from Earth than it takes to travel from the Moon to the Earth.
3. In my last house, when I used to put the electric kettle on in the kitchen at the same time as the washing machine was on in the laundry and the electric heater was on in the lounge room the fuse would blow and all the appliances would stop working. Why did it do this? Explain using circuit diagrams.