Question 4
FA driver sees a hazard and stops her car.
The Figure shows the velocity–time graph for the car from the moment the driver sees the hazard.
Figure
a.[1]
Use the Figure to determine the driver's reaction time.
b.[2]
Use the equation: distance=speed×time\text{distance} = \text{speed} \times \text{time}distance=speed×time
Calculate the thinking distance.
c.[3]
Use the equation: acceleration=change in velocitytime\text{acceleration} = \dfrac{\text{change in velocity}}{\text{time}}acceleration=timechange in velocity
Calculate the deceleration of the car while it is braking.
d.[2]
The driver makes the same stop on another day when she is very tired. The car has the same deceleration when braking.
Describe how the velocity–time graph would be different.
8.1 Physics on the move Questions
50 exam-style questions on OCR GCSE Physics 8.1 Physics on the move, covering 8.1.1 Typical everyday speeds, 8.1.2 Typical everyday accelerations, 8.1.3 Ratios, units and rates on the road, 8.1.4 Human reaction times, 8.1.5 Factors affecting stopping distance, 8.1.6 Stopping distances at different speeds, 8.1.7 Dangers of large decelerations, 8.1.8 Estimating forces in road situations, and 8.1.9 Estimating the effects of large accelerations. Each one has a worked solution and a mark scheme showing where the marks go.