Question

Multiple Choice
Police can estimate the speed of a vehicle before the brakes are applied using the formula 0.75d= s^2/30.25, where s is the speed in miles per hour and d is the length of the vehicle's skid marks. What was the approximate speed of a vehicle that left skid marks measuring 140 feet?
A) about 10 miles per hour
B) about 75 miles per hour
C) about 15 miles per hour
D) about 56 miles per hour

Answer 1

Simply solve for s when d=140.

Answer 2

To make it simpler let me do this...\[s=\sqrt{\frac{ 0.75d }{ 30.25 }}\] Now substitute 140 for d and punch your calculator!

Answer 3

C?

Answer 4

@smileyxl3

Answer 5

No I made an error! Its supposed to be \[s=\sqrt{(30.250)(0.75d)}\]

Answer 6

When d=140, s = 56.

Answer 7

oh ok, because I had got confused lol

Answer 8

I got D. 56

Answer 9

You solved it yourself, that's good!