Tarzan, in one tree, sights Jane in another tree. He grabs the end of a vine with length 20 m that makes an angle of 45 ? with the vertical, steps off his tree limb, and swings down and then up to Jane's open arms. When he arrives, his vine makes an angle of 30 ? with the vertical.
A. Calculate Tarzan's speed just before he reaches Jane. You can ignore air resistance and the mass of the vine.