Thread: Estimating Speed of a Vehicle

The speed a vehicle was traveling, s, in miles per hour, when the brakes were first applied, can be estimated using the formula:





where d is the length of the vehicle's skid marks, in feet.

a) Determine the speed of a car that made skid marks 4ft long.

b) Determine the speed of a car that made skid marks 16ft long.

c) Determine the speed of a car that made skid marks 256ft. long.

Originally Posted by camstill

The speed a vehicle was traveling, s, in miles per hour, when the brakes were first applied, can be estimated using the formula:





where d is the length of the vehicle's skid marks, in feet.

a) Determine the speed of a car that made skid marks 4ft long.

b) Determine the speed of a car that made skid marks 16ft long.

c) Determine the speed of a car that made skid marks 256ft. long.

Well then, these look like plug and chug kind of problems. They are all done the same way. Here's the first one.







miles/hr

I can't figure out the 2nd step to get to the 3rd step? Can you elaborate? Thank you!

Originally Posted by camstill

I can't figure out the 2nd step to get to the 3rd step? Can you elaborate? Thank you!

In the second step, after I substituted 4 for d, I divided 4 by .04.

I was forgeting the radical sign. Thank you so much for the help!