Posted by Jill on Sunday, November 22, 2009 at 3:49am.
a) A car is traveling at 50 mi/h when the brakes are fully applied, producing a constant deceleration of 40 ft/s^2. What is the distance covered before the car comes to a stop?
b) A car braked with a constant deceleration of 40 ft/s^2 and produced skid marks measuring 160 feet before coming to a stop. How fast was the car traveling when the brakes were first applied?

calc  drwls, Sunday, November 22, 2009 at 9:41am
a) Vo = 50 mph = 73.33 ft/s
Vo = sqrt (2 a X)
X = Vo^2/(2 a)
b) Use the Vo formula above, with X = 160 ft. The answer will be in ft/s.