Tarzan is in the path of a pack of stampeding elephants when Jane swings in on a rope vince, careing Tarzan to safety. The length of the vince is 25m and Jane starts her swing with the rope horizontal. If Jane’s mass is 54kg and Tarzan’s is 82 kg, to hwat hieght above the ground will the pair swing after she rescues him? Assume rope is vertical when she grabs him.

Initially

All this potential energy is converted to kinetic energy when Jane grabs Tarzan. So

When Jane and Tarzan come to rest

And that’s the wrong answer.