The diagram in figure shows a device which makes use of the principle of transmission of pressure.

(i) Name the parts labelled by the letters X and Y.

(ii) Describe what happens to the valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.

(iii) Give reasons for what happens to the valves A and B in part (ii).

(iv) What happens when the release valve is opened ?

(v) What happens to the valve B in cylinder P when the lever arm is moved up ?

(vi) Give a reason for your answer in part (v)

(vii) State one use of the above device.

Describe a simple experiment to demonstrate that a liquid enclosed in a vessel exerts pressure in all directions.

Deduce an expression for the pressure at a depth inside a liquid.

Draw a simple diagram of a hydraulic jack and explain it's working.