A train with mass $5.6 \times 10^5\,\text{kg}$ is stationary in a station.
At $t = 0\,\text{s}$, a resultant force acts on the train, so it begins to accelerate forwards.
Fig. 1.1 shows the train’s distance-time graph for the first $120\,\text{s}$.
(a(i))[3]
Use Fig. 1.1 to determine:
1. the train’s average speed over the $120\,\text{s}$
2. the train’s speed at time $t = 100\,\text{s}$.
(a(ii))[2]
Describe how the train’s acceleration at time $t = 100\,\text{s}$ is different from the acceleration at time $t = 20\,\text{s}$.
(b(i))[2]
The train’s initial acceleration is $0.75\,\text{m s}^{-2}$. Calculate the resultant force acting on the train at this moment.
(b(ii))[1]
At time $t = 120\,\text{s}$, the train starts to decelerate. State what is meant by deceleration.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Average speed = (4800 / 120) = 40 m/s” …