Fig. 2.1 depicts two engineers checking the length of a wall built from concrete. The wall has a height of $2.0\,\text{m}$, a length of $15\,\text{m}$ and a thickness of $0.25\,\text{m}$. Its weight is $180\,000\,\text{N}$ and its mass is $18\,000\,\text{kg}$.
(a)[1]
The engineers take one reading to find the length of the wall. State the name of the measuring instrument they use.
(b(i))[1]
Define the term density.
(b(ii))[2]
Calculate the density of the concrete.
(b(iii))[2]
Calculate the pressure produced by the wall on the ground.
(b(iv))[1]
Without doing any further calculation, explain why doubling the length of the wall does not alter the pressure it exerts on the ground.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Tape measure” …