Police can estimate the speed of a vehicle before the brakes are applied using the formula 0.75d equals s squared over 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 150 feet?

about 11 miles per hour

about 15 miles per hour

about 58 miles per hour

about 67 miles per hour

I set it up like this:
0.75(150) = (square root s) / 30.25
but I ended up getting s = 11581260 Is there something I'm missing? would that just be 11 miles per hour?

Question

Police can estimate the speed of a vehicle before the brakes are applied using the formula 0.75d equals s squared over 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 150 feet?

about 11 miles per hour

about 15 miles per hour

about 58 miles per hour

about 67 miles per hour

I set it up like this: 
0.75(150) = (square root s) / 30.25
but I ended up getting s = 11581260 Is there something I'm missing? would that just be 11 miles per hour?

anonymous · Answer

@hartnn

hartnn · Answer

the question has
$\Large 0.75d = \dfrac{s^2}{30.25}$
thats not what u did :)

anonymous · Answer

oh...I didn't do the s^2 part...

hartnn · Answer

you did 

0.75d = $\sqrt s/30.25$

anonymous · Answer

oh wait

anonymous · Answer

squared not square root....woooopssss my bad lol

anonymous · Answer

ah okay so 58 miles per hour :) thank you!

hartnn · Answer

yeah, i got approx 58.33 :)