Car Safety NEED PRACTICE QUESTIONS

Driving Test How far will a car travel (in meters) if it brakes while traveling at 30 mph? 23m

Driving Test How far will a car travel (in meters) if it brakes while traveling at 70 mph? 96m

Driving Test How far will a car travel (in meters) if it brakes while traveling at 40 mph? 36m

Driving Test How far will a car travel (in meters) if it brakes while traveling at 20 mph? 12m

Momentum Select and recall the equation for momentum for collisions Use the conservation of momentum to solve collision questions Relate momentum to impulse and force

For a particular change in momentum: Impact Times When a force acts on an object (changing its movement) its momentum changes. Ft = change mv For a particular change in momentum: The longer the time the force is applied the lower the force needs to be to get the change in momentum The shorter the time the force is applied the higher the force needs to be to get the change in momentum

Impact Time So in a collision, if the impact time is short, the force will be high (and so more dangerous and damaging) In groups: list as many ways as you can that a car is designed to increase impact time.

Air Bags

Seat Belts

Crumple Zones

Stopping Distances When a driver sees a hazard ahead two things have to happen before they stop in time. 1. They need to think about stopping 2. They need to apply the brakes

Stopping Distance = thinking distance + braking distance The distance the car travels while each of these happens are known as: the distance travelled while the driver reacts/thinks about stopping Thinking distance - the distance travelled from when the brake is applied to when the car comes to a stop. Braking distance - Stopping Distance = thinking distance + braking distance

Stopping Time The total time it takes for a vehicle to come to a stop Stopping time = thinking time + braking time Thinking time = time it takes for the driver to react Braking time = time from when the brake is applied to when the car comes to stop

READ THE QUESTION

Factors that affect stopping distance Factors that affect thinking distance Factors that affect braking distance Some factors affect both thinking and braking distance, some factors effect one or the other.

Factors that effect thinking distance Factors that effect braking distance Speed Alcohol/Drugs Weather/road conditions Tiredness Conditions of tyres/brakes Distractions Road surface

40 meters apart, placed in accident hotspots! Driving Test 40 meters apart, placed in accident hotspots!