A man is sitting in a bosun's chair that dangles from a massless, frictionless pulley and back down to the mans's hand. The combined mass of man and chair is 100 kg.

Question

With what force magnitude (N) must the man pull on the rope if he is to rise with a constant velocity? ..with an upward acceleration of 1.29 m/s2?

If the rope extends to the ground and is pulled by a co-worker, with what force magnitude must the co-worker pull for the man to rise with a constant velocity? .. and with an upward acceleration of 1.29 m/s2?

Draw the vector diagram.

Tension = mg+ma -handforce on the chair side.

On the rope side, Tension=handforce.

So solving, Tension= handforce

so handforce=(mg+ma) 1/2

but how do you determine what 'a' is?

.. when i try to solve for 'a'.. i reach a deadend with having to solve for T also.

hmm.. is it 0?

For constatn velocity F is 490N; for upward acceleration of 1.29 m/s2 it is 
554.9N 
For coworker F is 980N to rise with constant velocity and 1109N to rise with acceleration of 1.29.

Carl · Answer

You know that when he is moving with a constant velocity, a=0 , when he is moving with acceleration, a=1.29 m/s^2 . Now plug in the numbers you have into the equations and you will come up with the answers you provided.