Question

A ball rolls without slipping at 5 m/s off an incline of 15 degrees. The ball falls off the incline and enters a hole 4 meters below the incline. What is the horizontal distance between the bottom of the incline and the the hole.

I havent the foggiest how to start.

Answer 1

just realize that when the ball leaves the ramp, its horizontal speed remains constant at 5cos15°

How long does it take to fall 4 meters? 4.9t^2 = 4

use that time to see how far the ball travels horizontally.

Answer 2

this isnt giving me the proper answer, although its only off by a miniscule amount, the answer is supposed to be 4.4776, im getting 4.3636363

Answer 3

Hmmm. I also get 4.36

We forgot the ball's initial downward velocity of 5sin15° = -1.294 m/s. Unfortunately, that makes it worse, since it falls faster. Now we have to find t such that

-1.294t - 4.9t^2 = -4
t = 0.781

and that means the ball only goes

5cos15° * 0.781 = 3.77 m

See anything else we missed?