Brakes transfer a vehicle’s kinetic energy into thermal stores. Higher speed greatly increases the energy to remove because kinetic energy depends on speed squared. For the same constant braking force, work done equals the removed kinetic energy, so braking distance depends on speed squared; poor grip or faulty brakes increase the distance. Example: Explain why braking strongly can heat brakes. Work done by friction transfers kinetic energy into their thermal stores. Give a reason. Use evidence.