Tarzan tries to cross a river by swinging from one bank to the other on a vine that is 8.8 m long. His speed at the bottom of the swing is 7.2 m/s. Tarzan does not know that the vine has a breaking strength of 1.0 multiplied by 103 N. What is the largest mass that Tarzan can have and still make it safely across the river?

*I have the formula m=(Fr)/V^2 and I'm plugging the above numbers into that but it just is not working. Does anyone know how to approach this problem?*

You forgot to include Tarzan's weight to the tension in the vine. The vine must support the weight AND provide for centripetal acceleration.

M(g + V^2/R) = 1000 N

Solve for M