(a)[1]
State the meaning of pressure.
(b(i))[2]
Find the pressure produced by $25\,\text{m}$ of water.
(b(ii))[1]
Find the atmospheric pressure.
(c(i))[3]
Explain why the piston is driven into the cylinder as the depth gauge is lowered into the water.
(c(ii))[3]
Explain, in molecular terms, how the pressure of the trapped gas changes as the piston moves into the cylinder.
(c(iii))[2]
On Fig. 8.2, sketch a graph to show how the volume of trapped gas falls as the gauge is lowered into the water.
(c(iv))[1]
Suggest one reason why the dial needle must be reset to zero at the water surface each time it is used.
(c(v))[2]
Explain, in terms of the water molecules, why the density of the water stays constant.