"Rocket Man" has a propulsion unit strapped to his back. He starts from rest on the ground, fires the unit, and accelerates straight upward. At a height of 16 m, his speed is 5.5 m/s. His mass, including the propulsion unit, has the approximately constant value of 139 kg. Find the work done by the force generated by the propulsion unit.

Question

I tried solving for the force upward and got 2126.7N and then applied that to the Work equation (W = force*cos( )*distance) but it keeps saying I'm getting the wrong answer. I tried both 180 and 0 for the angle so I'm not sure what I'm doing wrong.

Answer 1

work done by unit=PE and Ke at16m, 5.5m/s

work done=mg(16)+1/2 m v^2