stopping distances

• stopping distance = thinking distance + breaking distance
• thinking distance is how far the car travels during the drivers reaction time
• breaking distance is the distance taken to stop under the breaking force
• thinking distance is affected by your speed and your reaction time
• breaking force is affected by your speed, the weather, road surface, condition of tyres, how good your breaks are
• the longer your stopping distance, the more space you need to leave front in order to stop safely
• when braking, this causes brake pads to push on wheels, causing friction, causing work to be done. the work done between brake and wheels transfers energy from the kinetic energy stores of the wheels to the thermal energy stores of the breaks. breaks increase in temperature
• the faster a vehicle is going, the more energy it has in its kinetic stores, so the more work done needs to be done to stop it. that means that a greater breaking force is need to make it stop
• larger breaking force means a large deceleration, can be dangerous as breaks may overheat or skidding.