Question

Tarzan, in one tree, sights Jane in another tree. He grabs

Answer 1

Answer:

He knocks her. V = 7.97m/s

Explanation:

Let A be Tarzan's starting position and B Jane's position (Tarzan's final position).

Since there is no air resistance, energy at position A must be equal to energy at B.

At position A, Tarzan's speed is zero and since the 45° of the vine is greater than the final 30°, Tarzan will have potential energy at point A.

$E_{A}=m_{T}*g*L*(cos(30)-cos(45))$

At point B, it is the lowest point (between A and B), so it has no potential energy. It will only have kinetic energy (ideally zero, for Jane's sake, but we don't know).

$E_{B}=\frac{m_{T}*V^{2}}{2}$

Because of energy conservation, we know that Ea=Eb, so:

$m_{T}*g*L*(cos(30)-cos(45))=\frac{m_{T}*V^{2}}{2}$  Solving for V:

$V=\sqrt{2*g*L*(cos(30)-cos(45))}=7.97m/s$