A heavy or fast vehicle increases the required braking heat because

A heavy or fast vehicle increases the required braking heat because

• A. The brakes must absorb more heat
• B. The brakes are cooling faster
• C. It doesn't affect heating
• D. It reduces tire wear

Answer: (A)

Braking heat rises because the brakes have to absorb more energy to slow the vehicle down. The energy that must be removed during a stop is the kinetic energy, which is 1/2 m v^2. A heavier vehicle or one moving faster carries more energy, so the braking system must dissipate more energy as heat. The more heat the brakes must absorb, the hotter they become, and if heat isn’t removed quickly enough, braking performance can fade. The other ideas don’t fit because cooling isn’t inherently faster with a heavier or faster vehicle, the heating effect does depend on energy (so it does affect heating), and reducing tire wear isn’t relevant to why braking heat increases here.

Braking heat rises because the brakes have to absorb more energy to slow the vehicle down. The energy that must be removed during a stop is the kinetic energy, which is 1/2 m v^2. A heavier vehicle or one moving faster carries more energy, so the braking system must dissipate more energy as heat. The more heat the brakes must absorb, the hotter they become, and if heat isn’t removed quickly enough, braking performance can fade. The other ideas don’t fit because cooling isn’t inherently faster with a heavier or faster vehicle, the heating effect does depend on energy (so it does affect heating), and reducing tire wear isn’t relevant to why braking heat increases here.