As a research submarine descends from the surface of a deep freshwater lake to a depth of 40 m, the total pressure acting on its outer hull increases from 100 000 Pa100\,000\text{ Pa}100000 Pa to 500 000 Pa500\,000\text{ Pa}500000 Pa. Which statement explains this increase in pressure?
The density of the lake water increases significantly with depth.
The gravitational field strength increases as the submarine gets closer to the Earth's center.
The weight of the water column above the submarine increases with depth.
Freshwater becomes highly compressed at greater depths.
188 exam-style questions on CIE IGCSE Physics Pressure, covering Pressure. Each one has a worked solution and a mark scheme showing where the marks go.