Stopping Distances (Edexcel GCSE Physics)

A car is travelling at 10 m/s.

The driver sees a danger and stops the car.

[1]

Figure 4 shows a speed-time graph for the driver stopping the car.

Figure 4

[2]

reaction time = .............................................................. s

Figure 5 shows the apparatus a student uses to investigate how the stopping distance of a toy car depends on the type of surface that it is stopping on.

Figure 5

Describe an experiment to find out how the stopping distance depends on the surface that stops the toy car.

Figure 6

[1]

[2]

average stopping distance = .............................................................. m

[1]

A car is travelling down a slope at 2.0 m/s.

The car accelerates for 4.0 s.

The speed of the car increases to 12 m/s.

Calculate the acceleration of the car.

Use the equation

acceleration of the car = .............................................................. m/s²

Write down an equation which relates thinking distance, braking distance and stopping distance. 

A truck driver is travelling along a road at 25 m/s when they spot red traffic lights 200 m ahead.

The truck driver has a reaction time of 0.84 s, however they are tired so their reaction time is twice as long. 

Calculate the truck driver's thinking distance.

Figure 1

25 m/s = 90 km/h. The lorry's brakes can produce a deceleration of 3.5 m/s².

Estimate the stopping distance of the lorry.

When the truck fully applies its brakes, it comes to rest only 5 m before the red light. 

Suggest two reasons why this may have happened.

A council introduces 20 miles per hour (mph) speed limit in a particular region of a city.

A member of the council states that drivers can react faster at 20 mph than they can at 30 mph.

Explain what is wrong with the councillor's statement.

Figure 1

Describe how thinking distance varies with increasing speed.

Use data from the graph in your answer.

Choose quantities from the box. 

Each quantity can be used once, more than once or not at all.

During a braking test, 900 kg car is travelling at 40 m/s.

The test driver must brake sharply and come to a complete stop when she sees a light flash at the end of the road.

Calculate the work done by the brakes to bring the car to a stop.

A car brake manufacturer states that their brakes can produce a maximum braking force of 6250 N.

Calculate the braking distance of the car from part (b) if the car is using these brakes.

In reality, after the light flashes the car travels further than the value calculated in (c). 

Explain why this happens.

A scientist uses different drivers to test the stopping distances of the same car.

Figure 1 shows the results.

Figure 1

Most of the drivers tested the car on a dry day, on a level road.

State which driver tested the car on a wet road.

State which driver has the shortest reaction time.

Calculate their reaction time, giving your answer to 1 significant figure.

The car has a mass of 1400kg.

[3]

[2]

[3]

Driver 2 travels at 24 m/s on the road. The thinking distance is 20m and the braking distance is 36 m.

Calculate the deceleration of the car.

You may assume the braking force is uniformly applied.