Car safety

Question 1

Define breaking distance.

Answer 1

The distance the car travels under the breaking force

Question 2

Define thinking distance.

Answer 2

The distance the car travels between the driver seeing a hazard and applying the breaks.

Question 3

Give four things that affect the breaking distance.

Answer 3

How fast you are going, how good your brakes are, how good the tyres are and how good the grip is (depending on road surface, weather conditions and tyres)

Question 4

Give two things that affect the thinking distance.

Answer 4

How fast you are going and how dopey you are (tiredness, drugs, alcohol)

Question 5

Describe how brakes work. Include energy transfers.

Answer 5

When you apply the brakes to slow down a car, work is done. The breaks reduce the kinetic energy of the car by transferring it into heat and sound energy.

Question 6

Describe what regenerative braking systems are, how they work and where they are used?

Answer 6

They are an alternative to ordinary brakes that are often seen in some electric or hybrid cars. They are a system that drives the vehicle to do the majority of the braking.

Question 7

Fill in the gaps. In a crash, there’ll be a big change in ______ over a very ______ time, so the people inside the car experience ______ forces that could be ______.

Answer 7

Momentum, short, huge, fatal.

Question 8

Name four ways that cars are designed to convert kinetic energy in the event of a crash describe in detail.

Answer 8

1. Crumple zones- these zones crumple at the front and the back of the car on impact. The car’s kinetic energy is converted into other forms of energy. These also increase the impact time, decreasing the force produced by the change in momentum.
2. Side impact bars- strong metal tubes fitted into car door panels. They help to direct the kinetic energy of the crash away from the passengers.
3. Seat belts- these stretch slightly, increasing the time taken for the wearer to stop