What is the formula for stopping distance?

What is the formula for stopping distance?

• A. S.D = R.D + B.D
• B. R.D + B.D = S.D
• C. B.D = S.D - R.D
• D. S.D = R.D - B.D

Answer: (B)

Stopping distance is made up of two parts: the distance you travel during your reaction time and the distance your vehicle travels while you brake. So the total stopping distance equals reaction distance plus braking distance. The given form R.D. + B.D. = S.D. is the same idea as S.D. = R.D. + B.D.—it's just rearranged, which is still correct. Subtracting braking distance from stopping distance would imply braking reduces the total in a way that doesn’t reflect how stopping works, so that form isn’t correct. In practice, you can think of it as S.D. = R.D. + B.D. or equivalently R.D. + B.D. = S.D. for the same relationship.

Stopping distance is made up of two parts: the distance you travel during your reaction time and the distance your vehicle travels while you brake. So the total stopping distance equals reaction distance plus braking distance.

The given form R.D. + B.D. = S.D. is the same idea as S.D. = R.D. + B.D.—it's just rearranged, which is still correct. Subtracting braking distance from stopping distance would imply braking reduces the total in a way that doesn’t reflect how stopping works, so that form isn’t correct. In practice, you can think of it as S.D. = R.D. + B.D. or equivalently R.D. + B.D. = S.D. for the same relationship.