Stopping Distances Practice Questions

State what is meant by the stopping distance of a car.

Calculate the thinking distance of the car.

Thinking distance = ............... m

Calculate the stopping distance of the car.

Stopping distance = ............... m

Which of the following gives a typical range of human reaction times?

Tick one box.

• $0.002$ s to $0.009$ s
• $0.02$ s to $0.09$ s
• $0.2$ s to $0.9$ s
• $2$ s to $9$ s

Give two factors that could increase a driver's reaction time.

A road safety poster states: 'Twice the reaction time means twice the stopping distance.'

Explain why this statement is not correct.

Describe how the students could use a metre ruler to measure a reaction time.

Calculate the mean reaction time for student A.

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

The mean reaction time for student B is $0.43$ s.

Both students drive cars at $25$ m/s.

Calculate how much greater the thinking distance would be for student B than for student A.

Give one reason why the students carried out five tests each, rather than one test each.

Calculate the reaction time of the driver.

Reaction time = ............... s

Compare how the thinking distance and the braking distance change when the speed of the car doubles from $10$ m/s to $20$ m/s. Use data from the table.

Estimate the stopping distance of this car at a speed of $25$ m/s.

Use data from the table.

Stopping distance = ............... m

Use the data in the table to explain why speed limits are lower in towns than on motorways.

Explain, in terms of energy, why the temperature of the brakes increases as the cyclist brakes.

Explain one reason why braking hard for a long time can make the brakes less effective.

A car driver brakes very suddenly on a wet road, causing a very large deceleration.

Give two dangers caused by a very large deceleration.

Calculate how much further a tired driver (awake for 18 hours) would travel during their reaction time than an alert driver, when both are driving at $30$ m/s.

A student says:

'Using a hands-free phone while driving is safe, because the reaction time is still inside the typical range of $0.2$ s to $0.9$ s.'

Evaluate this statement. Use data from the table.

The results in the table show the effect of each condition on thinking distance only.

Give one factor, other than speed, that would increase the braking distance of a car, and explain why.

Calculate the kinetic energy of the lorry at $20$ m/s.

Use the equation:

$E_k = \dfrac{1}{2}mv^2$

Estimate the average braking force acting on the lorry.

Average braking force = ............... N

Calculate the deceleration of the lorry during braking.

Deceleration = ............... m/s$^2$

The same lorry travels at $30$ m/s on a different road. The maximum braking force the lorry can produce is unchanged.

Calculate the braking distance of the lorry at $30$ m/s.

Braking distance = ............... m