Hi I'm AllAmericanGirl2004, I need some serious help in my AP Physics class. This last unit, on forces is nearly killing me. Maybe you guys can help me understand this. Here's a problem I'm stuck on... Tarzan plans to cross a gorge by swinging in an arc from a hanging vine. If his arms are capable of exerting a force of 1600 N, what is the max speed he can tolerate at the lowest point of his swing? His mass is 80kg and the vine is 6.8 m long. Now, it seems to me that the net force is 1600 N and since Tarzan's mass is 80kg, wouldn't you just say that using the F=ma equation that 1600=80a? But that seems way too easy....I don't know. HELP!!!