Question

A certain car traveling at 34.0 mph skids to a stop in 29 meters from the point where the brakes were applied. in approximately what distance would the car have stopped had it been going 105.4 mph?

Answer 1

Using the kinematic equations: (final velocity)^2 = (initial velocity)^2 - 2 * acceleration * distance Assuming the acceleration/deceleration on the car is constant from a constant force on the brakes. Converting from mph to m/s using 0.447 (so 34 mph is 15.2 m/s) (0)^2 = (15.2)^2 - 2 * acceleration * 29 acceleration = 4.0 m/s^2 Had the car been going 105.4 mph (47.1 m/s) (0)^2 = (47.1)^2 - 2 * 4 * distance distance = 277 meters