How many times the distance does it take to stop from 60 mph compared to stopping from 30 mph?

When a vehicle is in motion, the distance it requires to come to a complete stop is influenced by its speed and the laws of physics, particularly the kinetic energy involved. Kinetic energy increases with the square of the speed. This means if a vehicle is traveling at a higher speed, it has significantly more energy that needs to be dissipated in order to come to a stop.

Specifically, when comparing stopping distances, the relationship can be understood through the equation for kinetic energy: KE = 1/2 mv^2, where 'm' is mass and 'v' is velocity. The stopping distance increases with the square of the speed: if you double the speed, the stopping distance quadruples.

So, when comparing stopping from 30 mph (which is 30 mph) to stopping from 60 mph (which is double that speed), the stopping distance at 60 mph becomes four times greater. This is because stopping from 60 mph requires dissipating four times the kinetic energy compared to stopping from 30 mph.

Using this understanding, the correct answer signifies that the stopping distance from 60 mph is four times the stopping distance from 30 mph, reinforcing the concept of how speed dramatically affects stopping distances.