Stopping Distances Practice Questions

Calculate the stopping distance of the car at a speed of $20$ m/s.

Use data from the table to calculate the driver's reaction time.

State one factor, other than the speed of the car, that would increase the braking distance.

Which of these is closest to a typical human reaction time?

• A $0.002$ s
• B $0.02$ s
• C $0.2$ s
• D $2$ s

Describe a method the students could use to measure a person's reaction time using a $30$ cm ruler.

Calculate the kinetic energy of the car at $18$ m/s.

Calculate the average braking force acting on the car.

The brake discs of the car become very hot while the car is braking.

Explain, in terms of energy, why this happens.

The thinking distance is the same on both journeys.

Explain why.

Explain why the braking distance of the fully loaded van is greater than the braking distance of the empty van.

Use data from the table to show that the results fit the equation $d = kv^2$, and calculate a value for $k$.

Give a unit for $k$.

Calculate the braking distance of this car from a speed of $30$ m/s on the same track.

The driver of the car has a reaction time of $0.60$ s.

Calculate the total stopping distance of the car from a speed of $30$ m/s.

Give two factors, other than using a phone, that increase a driver's reaction time.

Explain why using a mobile phone increases the total stopping distance of a car, even when the brakes and tyres are in perfect condition.

State one change in the condition of the road that would increase the braking distance.

Calculate the thinking distance of the moving car.

Deduce whether the moving car will hit the stopped car. You must show your working.

Explain how the stopping distance would be different if the same journey were made on a wet road at the same speed.

Show that the braking distance of the lorry is about $125$ m.

The same lorry brakes from a speed of $20$ m/s with the same braking force.

Calculate the new braking distance.

Use the equations for kinetic energy and work done to explain why the braking distance of this lorry is proportional to the square of its initial speed.