Question

laws of motion - physics

Answer 1

the law of motion is that (every action there is an equal and opposite reaction).

Answer 2

given, m=50kg
and net acceleration of elevator = g/3 (up)
then,
net force on elevator floor =50× (g/3) =500/3 N
as we know,
net work done= net force× distance traveled
(500/3)×12 = 500×4 =2000 jule

hence the answer is (a)

I hope this will help you....