1) The diagram below shows the structure of a simple hydraulic lift. When a force F is applied at M, a force is set up at N to lift a load.

What is the magnitude of force F exerted in order to lift a load of 80N at N?

2) The diagram shows a simple mercury barometer.

When the mercury barometer is brought to the top of a mountain, the height h of the mercury column decreases.

Which statement explains this?

3) The diagram shows a faulty barometer which has air trapped above the mercury in the tube. H is measured from the surface of the mercury in the reservoir to the surface of the mercury in the tube.

If the tube is slightly lowered into the reservoir, the distance H will

4) A sink is filled to a depth of 0.20 m with a liquid of density 1100 kg/m^–3.

The gravitational field strength is 10 N/kg.

What is the pressure on the base of the sink due to the liquid?

5) One side of a vertical garden fence has an area of 4.0 m². A strong wind blows on one side of the fence and increases the pressure to 105 kPa. The pressure on the other side of the fence is 103 kPa.

What is the resultant force on the fence?