Question

A car’s speed before a sudden stop can be estimated by the formula

S = √(30gk) , where
S = speed of the car in mph,
g = drag factor, and
k = length of skid mark in feet.
The drag factor during a recent crash was 1. What was the approximate speed of the car if it created skid marks 30 feet long?
a. 30 mph
b. 45 mph
c. 60 mph
d. 90 mph

Answer 1

S = 30 mph

Explanation:

A car’s speed before a sudden stop can be estimated by the formula :

`S=√(30gk)`

Here,

S = speed of the car in mph,

g = drag factor, and

k = length of skid mark in feet

If drag factor is 1, k = 30 feet

So,

`S=√(30* 1* 30)\\\\S=30\ mph`

Therefore, the correct option is (a) 30 mph.