Please look at the attached screenshot.
This problem is really confusing for me and I can't seem to make much sense out of it.
Ei = Ef
The Attempt at a Solution
As you can see, I did get (a). (The other checkmarks, I guessed — there were only two possible choices for each, anyway.) KEi = KEf + 15, and by plugging in appropriate numbers, I was able to get v = 1.9464 m/s.
But as for (b), (c) and (d), I've no idea how to approach them.
I did try (c), and this time using KEi = KEf + 35, I realized there wouldn't be a valid v, and thus proceeded to determine the turning point. Hence my new equation was KEi = mgh, from which I got h=2.1556 m, but that's vertical. We want horizontal distance, however. So using the ratio (1:35/(mg)) = (x:2.1556), x= 0.4707. However, that is wrong.
As for forces, I don't know how to get started.
Please help — I don't know what to do anymore!