Problem 7-51 Energy cons. - Part 4 - C

A boy is playing with a rope tied to a tree near his favourite swimming hole. Initially the boy is stationary and the rope (of length 3.7m) makes an angle of 48 with the vertical. He then lifts his feet slightly and starts to swing freely. If air resistance is neglected, use conservation of energy to determine:

(a) his speed at the bottom of the swing
(b) the minimum height, relative to his initial position, to which he can swing.

Diagram of a tree on the edge of a cliff with water below. A rope hangs from a branch hanging over the water.


Accumulated Solution

Diagram of angle of rope

At point 2, EP=0

At point 2, EK=(1/2)mv2


No. But close. What is 3.7cos48 on the drawing and where is the origin?

Try again.