Question

To reduce speed while going down a steep hill, do which of the following?

a. Apply brakes continuously
b. Downshift to a lower gear
c. Accelerate to gain control
d. Turn off the engine

Answer 1

To safely reduce speed on a steep hill, downshifting to a lower gear is the best option as it uses engine resistance to slow the car, similar to other mechanisms that convert kinetic energy to another form for deceleration.

Step-by-step explanation:

To reduce speed while going down a steep hill, the best option is downshifting to a lower gear (option b). This is because downshifting allows the engine to help in slowing down the vehicle through a process called engine braking. When you downshift, the engine runs at a higher RPM (revolutions per minute) and this resistance helps in slowing the vehicle down. Moreover, continuously applying brakes (option a) can lead to brake overheating and possible failure, which is dangerous. Therefore, downshifting is the safer and more effective method to control speed on steep descents.

Relating this to physics and energy conversion, when you downshift to a lower gear, you are essentially allowing the car's kinetic energy to be partially converted into thermal energy due to engine resistance, similar to how a hybrid car charges its batteries during deceleration or how airplane flaps use air resistance to slow down for landing.