What Minimum Speed Must Jane Have to Swing Across the River?

[alevis]

Homework Statement

Vernie, whose mass is 45.0 kg, needs to swing across a river filled with crocodiles in order to rescue Charlie,whose mass is 75.0 kg. However, she must swing into a constant horizontal wind force on a vine that is
initially at an angle of θ with the vertical. The width of the river between them is D = 60.0 m, F = 120 N, Length of

the rope L = 45.0 m, and θ = 60.0°.
(a) With what minimum speed must Jane begin her swing in order to just make it to the other side?
(b) Once the rescue is complete, Vernie and Charlie must swing back across the river. With what minimum

speed must they begin their swing?

Homework Equations

L=L-(Lcosθ)
KE = 1/2mv²
PE = mgh.

The Attempt at a Solution

PE = KE
mgh = 1/2mv²

 

[Doc Al]

You posted an almost identical problem here: https://www.physicsforums.com/showthread.php?t=284193

Which is the one you're actually working on?