Stopping Distances
What factors affect this?
How to calculate
Mass of the vehicle
Speed of the vehicle
Stopping distance is calculated by: stopping distance = thinking distance + braking distance
Formula for thinking distance: thinking distance = speed x reaction time
Reaction time
This can, in turn, be affected by:
Tiredness
Alcohol consumption
Drugs
Distractions (using a mobile phone)
Friction (of the tyres on the road)
This is affected by wet or icy roads. As a result, drivers are required to brake with less force to avoid skidding. This increase the stopping distance.
The greater the mass of the vehicle, the greater the momentum it has (momentum = mass x velocity). This means more force is required to stop the car and so the braking distance is increased.
The greater the speed, the greater the stopping distance. This is because with increased speed comes increased reaction (thinking distance) and braking distance.
Definition
The shortest distance a vehicle can stop in
It can be displayed in two parts
Thinking distance
Braking Distance
This is the distance travelled by the vehicle in the driver's reaction time (of applying the brakes).
This the distance travelled by the car during the time that the braking force is active
The condition of the brakes and tyres
The worse the condition, the greater the stopping distance as they won't be as effective.
The equation: Force = mass x acceleration can be used to calculate braking force