Elevator's Weight or Gravity Pulls?
Classical Mechanics
Level
pending
A system of pulley was used in order to pull up an elevator. At 1500 kg, the elevator is lifted up 40 m by the cable's pull. Let A be the work done by the elevator itself, while B the cable's work. Add the two works in terms of Joules.
The answer is 648000.
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1 solution
Solution for A: Since it is the work done by the elevator ITSELF, therefore the weight is the force, so the work is equal to W = (1500 N)(40 m) = 60 000 J.
Solution for B: Much easier part - the cable does the pulling, so it pulls the mass with the gravity in certain height. Therefore the work is equal to W = (1500 N)(9.8 m/s^2)(40 m) = 588 000 J.
Adding those two, the answer is 648 000 J.