Vehicle Safety and Momentum
Stopping distances could literally save your life. Total stopping distance equals thinking distance plus braking distance. Your reaction time affects thinking distance (tiredness, distractions, alcohol all make it worse), while speed, road conditions, and tyre quality affect braking distance.
When brakes work, they convert the vehicle's kinetic energy into heat through friction. Go faster and you need much more braking force to stop in the same distance - which is why speed limits exist and why brakes can overheat.
Momentum is always conserved in collisions and explosions momentum=mass×velocity. This principle helps crash investigators work out what happened and engineers design safer vehicles.
Safety features work by increasing the time taken to stop, which reduces the force experienced. Seatbelts stretch slightly, airbags inflate to cushion impact, and crumple zones deform - all designed to reduce the rate of momentum change and keep forces survivable.
Life skill alert: Understanding stopping distances isn't just for exams - it's crucial knowledge for when you start driving. Speed kills because braking distance increases dramatically with velocity.