Physics Problem Help: Chin-Up Force & Velocity

[kavdhaliwal]

I am working on a physics problem which states:
A person doing a chin-up 700N exclusive of the arms. During the first 25.0 cm of the lift, each arm exerts an upward force of 355 N on the torso. If the upward movement starts from resdt, what is the person's velocity at this point?

This is probably very basic, but I am having trouble with this whole energy, work, force, tension thing.

 

[hotvette]

Explain what you've tried and what equations are relevant. Have you drawn a free body diagram and labeled the forces?

 

[physumr]

You should have these formulas, derive an expression for final velocity and then plug in your numbers

Kf – Ki + Uf – Ui = Wnc
1/2mVf-1/2Vi+mgyf-mgyi=Wnc