Answered

A mechanic uses a mechanical lift to raise a car. The car weighs 11,000 N. The lift raises the car 2.5 m.


How much work is required to accomplish this task?


A.

27,500 J


B.

4400 J


C.

2.27 x 10-4 J


D.

22,500 J

Verified Answer :

Hippalectryon

The car gains Ep=massgdifference_in_height=11000*2.5=27500 J

Answer A

AL2006


Potential energy = (weight) x (height)

After the car has been raised 2.5 meters, it has

                 (11,000) x (2.5) = 27,500 Joules

MORE potential energy than it had before it was lifted.

That's the energy that has to come from the work you do to lift it.

Since no mechanical process is ever 100% efficient, the work required
to accomplish this task is at least  27,500 joules.


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