Topic 2 - Forces And Motion - Vehicle Stopping Distances Flashcards
What is the distance traveled before a driver reacts to a hazard called?
Thinking Distance
The distance traveled during the reaction time before the driver begins to brake.
What is the distance required to stop a vehicle after the brakes are applied called?
Braking Distance
This is the distance the vehicle travels while it decelerates to a stop.
What factors affect Thinking Distance?
- Speed
- Reaction time
- Concentration
- Tiredness
- Distractions
- Influence of drugs/alcohol
These factors can significantly impact how quickly a driver can react to a hazard.
What factors can influence Braking Distance?
- Speed
- Poor road conditions (icy, wet)
- Bald tires (low friction)
- Worn brake pads
- Mass (more passengers)
These factors determine how quickly a vehicle can come to a stop once the brakes are applied.
True or False: Braking Distance is only influenced by the speed of the vehicle.
False
Braking Distance is influenced by multiple factors, including road conditions and vehicle maintenance.
Fill in the blank: The distance traveled during the reaction time is known as _______.
Thinking Distance
Fill in the blank: The distance a car travels after applying brakes until it stops is called _______.
Braking Distance
What is the typical stopping distance at 20 mph?
6 m (12 metres or 40 feet)
This distance is approximately three car lengths.
How does the stopping distance change at 30 mph?
23 metres (75 feet)
This includes a thinking distance of 9 m and a braking distance of 14 m.
What is the thinking distance at 40 mph?
12 m
The total stopping distance is 36 metres (118 feet).
At 50 mph, what is the total stopping distance?
53 metres (175 feet)
This consists of a thinking distance of 15 m and a braking distance of 38 m.
What is the braking distance at 60 mph?
55 m
The total stopping distance is 73 metres (240 feet) with a thinking distance of 18 m.
What is the approximate stopping distance at 70 mph?
96 metres (315 feet)
This is equivalent to twenty-four car lengths.
What factors can affect stopping distances?
- Attention (thinking distance)
- Road surface
- Weather conditions
- Condition of the vehicle
These factors can lead to variations in the general guide for stopping distances.
True or False: The greater the speed, the greater the distance traveled during the same reaction time.
True
Higher speeds result in longer distances covered before the brakes are applied.
What happens to momentum during a crash?
Before the crash, there is a large momentum; after the crash, there is no momentum
This change in momentum results in a large force being felt.
How is force calculated in terms of momentum during a crash?
Force = mass x acceleration
A large deceleration results in a significant force exerted on the car and passengers.
What is the average mass of a car used to estimate forces on the road?
1500 kg
This value can be used along with acceleration to calculate the forces involved in a crash.
Fill in the blank: The stopping distance at 30 mph is ______.
23 metres (75 feet)
This includes a thinking distance of 9 m and a braking distance of 14 m.
What is the work done to stop a vehicle equal to?
The initial kinetic energy (KE) of the vehicle
What must happen to all the kinetic energy of a car for it to stop?
It must be transferred to friction
What is the relationship between braking distance and work done?
Work done = KE = Fd = 1 mu
Fill in the blank: The work done to stop a vehicle is equal to the initial _____ of the vehicle.
kinetic energy
True or False: The work done to stop a vehicle does not depend on its initial kinetic energy.
False
