Haloke does 176 j of work lifting himself 0.300m at a constant speed. what is haloke's mass?

Since he's lifting himself at constant speed ... not accelerating ... the net vertical force on
him is zero, meaning that he must be lifting with force that's exactly equal to his weight.

Potential energy he added during the lift = (mass) x (gravity) x (height)

Mass = (energy) / (gravity x height) = 176 / (9.8 x 0.3) = 59.864 kg