3.1 - Motion

Question 1

Define stopping distance.

Answer 1

Total distance travelled from when driver sees something requiring them to stop, to the point they actually stop.

Question 2

What two components does stopping distance consist of?

Answer 2

Thinking distance, breaking distance.

Question 3

What is thinking distance proportionate to?

Answer 3

Initial speed.

Question 4

How can you calculate thinking distance?

Answer 4

Initial speed x Reaction Time

Question 5

What influences a driver’s reaction time?

Answer 5

Tiredness, alcohol/drugs, distractions (mobile phone)

Question 6

Why is breaking distance proportionate to square of initial speed?

Answer 6

For the car to stop, all kinetic energy must be dissipated by the brakes, and KE = 1/2 mv^2

Question 7

Alongside the car’s initial speed, what is breaking distance also increased by?

Answer 7

Poor road conditions and car conditions (bald tyres, poor breaks, heavy load).