1) The Lunar Roving Vehicle (LRV) was an electric vehicle designed to give astronauts extra mobility when conducting missions on the Moon. It was made largely of aluminium, a relatively light metal, so as to reduce the overall mass of the vehicle. As a result, the LRV had a mass of 210 kg when empty.

Gravitational field strength on the Moon: 2 N/kg
Gravitational field strength on Earth: 10 N/kg

Suppose that the LRV broke down, and had to be pushed back to the spacecraft by the astronauts.

Ignoring the resistive effect of friction and air resistance, calculate the force needed to give the LRV a horizontal acceleration of 1.0 m/s² on the Moon and on Earth.

2) A block of wood is at rest on a sloping ramp. The forces acting on the block are weight W of the block, the friction F between the block and the ramp, and the normal contact force N exerted by the ramp.

Which free-body diagram is correct?

3) The diagram below shows five blocks of equal masses connected by four identical strings. They are pulled by a steadily increasing force F to the left on a smooth surface.

Which string (A, B, C or D) is least likely to break first?

4) A steel rod is supported by two spring balances as shown.

What is the weight of the steel rod?

5) The diagram shows a car moving forwards. Four forces acting on it are P, Q, R and S.

Which force(s), when increased in value, will cause the car to increase in speed?