8.4- ON THE ROAD

Question 1

What is thinking distance?

Answer 1

distance travelled by vehicle in time it takes for driver to react

Question 2

Equation for thinking distance for vehicle moving at constant speed?

Answer 2

distance = speed * time

time- reaction time

Question 3

What is the reaction time of a driver affected by? (3)

Answer 3

distractions
drugs
alcohol

Question 4

As reaction time is affected by distractions, drugs, alcohols, what is done in the UK?

Answer 4

drivers banned from using mobile phones while driving + breathalyser tests carried out on drivers

Question 5

What is the braking distance?

Answer 5

distance travelled by car in time it takes to stop safely , from when brakes first applied

Question 6

Assuming constant acceleration, a, to zero speed from speed u, what is the equation for braking distance?

Answer 6

s = u^2 / 2a

since u^2 = 2as

Question 7

What is the stopping distance?

Answer 7

thinking distance + braking distance

Question 8

What is the equation for stopping distance?

Answer 8

= ut+ u^2/ 2a

Question 9

Practical: testing friction

Answer 9

measure limiting friction between underside of block + surface it’s on
pull block with increasing force until it slides
limiting frictional force on block equal to pull force on block just before sliding occurs
find out how this force depends on weight of block