9.4 - on the road

Question 1

Define thinking distance

• give its equation

Answer 1

distance traveled by a vehicle int he time it takes the driver to react

• s = ut

Question 2

what affects thinking distance

Answer 2

• distractions (phone)
• drugs
• alcohol
• tirdness

Question 3

Define breaking distance

• give its equation (for constant deceleration)

Answer 3

distance traveled by a vehicle in the time it takes to stop safely

• S = U² / 2a

Question 4

what affects breaking distance

Answer 4

vehicles speed

road surface

weather conditions

tire condition

Question 5

define stopping distance

• give it equation

Answer 5

thinking + breaking distance

• ut + u²/2a

Question 6

Stopping distances

20 to 70 mph

Answer 6

Question 7

measuring limiting friction

• method
• diagram

Answer 7

• pull block with increasing force until it slides
• limiting frictional force = & opposite to the pull force on the block before it slides (read on scales of Newton meter)

(force is dependent on blocks weight)

Question 8

How does skidding occur

• what do cars have to prevent this

Answer 8

if the vehicle tries to slow down rapidly from moving at a high speed, the limiting frictional force between the road and tires can be exceeded.

This causes the breaks to lock, and it slides forward with the wheels being stationary.

• ABS (anti-lock break system)