Fig. 4.1 shows a tall vertical tube, closed at the lower end and open at the upper end.
The tube has a length of $1.0\,\text{m}$.
The tube’s cross-sectional area is $4.0 \times 10^{-4}\,\text{m}^2$.
It contains a liquid with density $1.4 \times 10^{4}\,\text{kg m}^{-3}$.
The atmospheric pressure is $1.0 \times 10^{5}\,\text{Pa}$.
(a(i))[3]
Calculate the total pressure in the liquid at the base of the tube.
(a(ii))[2]
Calculate the force acting on the inner surface at the bottom of the tube.
(b(i))[3]
Describe what occurs in the inverted tube when the glass sheet is taken away.
(b(ii))[2]
This apparatus is used to obtain a measurement that allows atmospheric pressure to be calculated.
Describe the measurement taken and then used in the atmospheric pressure calculation.
You may draw a diagram to support your description.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The pressure increase is given by $\Delta p=\rho gh$, or by $1.0 \times 1.4 \times 10⁴ \times 9.8$.” …