A car with mass $m$ moves along a straight, horizontal road at constant speed $v$.
At $t = 0$, the driver spots an obstruction ahead in the road and puts on the brakes.
The car does not start to decelerate at $t = 0$.
(a)[2]
State the meaning of deceleration.
(b)[1]
Suggest one reason why the car does not start to decelerate at $t = 0$.
(c(i))[1]
State the graph property on a distance-time graph that represents speed.
(c(ii))[2]
Using Fig. 1.1, find the initial speed $v$ of the car.
(d(i))[1]
Explain why the car's deceleration is greater than $\frac{F}{m}$.
(d(ii))[2]
Explain why the deceleration is not constant.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “a negative acceleration, or a reduction in velocity” …