Question

After an accident, police can estimate the speed that a car was traveling by measuring its skid marks. The formula S(L) = 2/5L can be used where S(L) is the speed, in

miles per hour, and L is the length of the skid marks, in feet. Estimate the speed of a car that left skid marks 90 ft long.
Approximately how fast was the car traveling if it left skid marks 90 ft long?
mph
(Simplify your answer. Type an integer or a decimal. Round to the nearest tenth.)

Answer 1

Car speed was approximately 40 mph.

Explanation:

Given:

Length of skid marks = 90 ft.

Police calculate the speed using formula:

S(L) = 2/5 L

Where,

S(L) = speed, in miles per hour.

L = the length of the skid marks, in feet.

Now Substituting the value of Length of Skid marks in above formula we get speed of car as;

Speed of car =
`(2)/(5)* 90 = 2* 18 = 36\ mph`

Rounding the above Answer to nearest tenth we get;

Speed of car was approximately 40 mph.