Which statement about stopping distances is true when your speed increases from 30 mph to 60 mph?

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Multiple Choice

Which statement about stopping distances is true when your speed increases from 30 mph to 60 mph?

Explanation:
Stopping distance is made up of two parts: the distance you cover while reacting to a hazard, and the distance your vehicle travels while braking. The first part increases directly with speed—if you’re going twice as fast, you cover roughly twice as much ground in the same reaction time. The braking part, however, grows even faster with speed because you have more kinetic energy to dissipate; braking distance increases with the square of speed. So going from 30 mph to 60 mph, the reaction portion roughly doubles and the braking portion grows by about a factor of four. The total stopping distance becomes much longer, not shorter. In short, higher speeds require much more distance to stop, which is why reducing speed reduces stopping distance.

Stopping distance is made up of two parts: the distance you cover while reacting to a hazard, and the distance your vehicle travels while braking. The first part increases directly with speed—if you’re going twice as fast, you cover roughly twice as much ground in the same reaction time. The braking part, however, grows even faster with speed because you have more kinetic energy to dissipate; braking distance increases with the square of speed. So going from 30 mph to 60 mph, the reaction portion roughly doubles and the braking portion grows by about a factor of four. The total stopping distance becomes much longer, not shorter. In short, higher speeds require much more distance to stop, which is why reducing speed reduces stopping distance.

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