A glass beaker with mass $m$ is stationary on a horizontal surface. The base of the beaker is a circle of radius $r$. Fig. 2.1 shows the beaker while liquid from container X is being poured in. At the beginning, the beaker is empty. At time $t = 0$, the tap is opened and liquid from container X flows slowly into the beaker at a constant rate. At time $t = T$, the liquid stops flowing into the beaker.
(a)[2]
The beaker exerts a pressure on the horizontal surface. Determine an expression for this pressure in terms of the gravitational field strength $g$, $m$ and $r$.
(b)[3]
Sketch on Fig. 2.2 to indicate how the pressure acting on the horizontal surface changes from $t = 0$ to $t = 2T$.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Clear indication that pressure ∝ 1 / area or that mg appears” …