Brutus, a champion weightlifter raises 240 kg of weights a distance of 2.35 m?

Question

Hey guys! I hope you can help me with these two physics problems. I really do appreciate it.:)

1) Brutus, a champion weightlifter raises 240 kg of weights a distance of 2.35 m.
a. How much work is done by Brutus lifting the weights?
b. How much work is done by Brutus holding the weights above his head?
c. How much work is done by Brutus lowering them back to the ground?
d. Does Brutus do work if he lets go of the weights and they fall back to the ground?
e. If Brutus completes the lift in 2.5 s, how much power is developed?

2) A force of 300 N is used to push a 145 kg mass 30 m horizontally in 3 s. Calculate the work done on the mass and the power developed.

Thanks! And can you please explain to me how you got the answers? :)

Answer 1

Rocky would probably know.

Answer 2

The answer can be derived by looking at similar problems in any standard physics textbook. There are some simple (primitive) formulas usually found in chapters "Work and Energy" or similar ones. With a modicum of effort and 3 minutes of time, one can obtain the answers to the problem. Even with percursory reading of any entry level physics textbook, one can arrive to all the answers in this very basic problem. Hope this helps.

Answer 3

mgh

mgh/t

mad

mad/t