Friction And Driving (T1)

Question 1

Describe friction and what causes it..

Answer 1

• friction is the force that causes moving objects to slow down and finally stop
• the kinetic energy of the moving object is converted to heat as work is done by the friction force
• friction occurs when solid objects rub against other solid objects and also when objects move through fluids (liquids and gases)

Question 2

How can reducing friction help with regards to machinery?

Answer 2

Reducing friction can mean machines work more efficiently by wasting less energy, and don’t wear out so quickly

Question 3

In what situation would increasing friction help?

Answer 3

Increasing friction can help tyres that grip the road better and make more effective brakes.

Question 4

How do the brakes on cars and bikes work?

Answer 4

By increasing the friction between the rotating wheels and the body of the vehicle

Question 5

Name three things the friction between the tyres and the road depends on.

Answer 5

• the road surface
• the tread in the tyres
• the weight of the vehicle

Question 6

When does skidding occur?

Answer 6

When the brakes are applied too hard and the tyres cannot grip the road surface.

Question 7

What is ABS?

Answer 7

• ANTI-LOCK BRAKING SYSTEM
• a computer controlled system fitted in most modern cars that senses when a car is about to skid and momentarily releases the brakes

Question 8

Explain what the ‘stopping distance’ of a vehicle is?

Answer 8

The stopping distance of a vehicle is the sum of the thinking distance (the reaction time of the driver) and the braking distance (how long the car takes to stop)

Question 9

Name some variables that can affect the reaction time of a driver..

Answer 9

• mental alertness
• visibility
• intoxification