- #1
hey123a
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Homework Statement
A cable lifts a 1200
kg elevator at a constant velocity for
a distance of 35 m. What is the work done by
(a)
the tension in the cable and
(b)
the elevator's weight?
Homework Equations
W = fscos(theta)
The Attempt at a Solution
okay i already know the answer to the solution and how to do it, however, when i first interpreted the question i thought the answer was zero because it says that it moves at a constant velocity. if its at a constant velocity then acceleration is zero. since f = ma, and acceleration is zero then force is equal to zero, so that means work is also equal to zero since W=fscos(theta)
however the answer to the question is actually
Solution: (a) 4.1 x 10 5J, (b) -4.1 x 10 5J
again, i know how to get the right answer but i would like to know what was wrong with my initial thinking