What Is Tarzan's Maximum Tolerable Speed When Swinging on a Vine?

[jordanb23]

i have one question that i need help on

Tarzan plans to cross a gorge by swinging in an arc from a hanging vine (Fig. 5-41). If his arms are capable of exerting a force of 2000 N on the rope, what is the maximum speed he can tolerate at the lowest point of his swing? His mass is 70 kg and the vine is 4.8 m long.

i diont know how to start and what formulas to use
can someone please help me

 

[andrevdh]

Welcome to PhysicsForums Jordan. Hope we can help you with some of your physics problems.

Tarzan will swing along a circular path if he hangs onto the vine. His speed will increase towards the bottom and will be a maximum at the lowest point. Motion in a circle requires that a centripetal force be exerted on Tarzan. Now according to Newton's third law if he exerts a 2000 N pulling force on the vine (he needs to pull himself up on the vine) the vine will exert a force of similar magnitude on him. This force is the centripetal force that will help him to swing along a circular path. Do you now how the centripetal force will be related to his speed? Or his centripetal acceleration?