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Question
If the tension in the cable supporting an elevator is equal to the weight of the elevator, the elevator may be
(a) going up with increasing speed
(b) going down with increasing speed
(c) going up with uniform speed
(d) going down with uniform speed
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Solution
(c) going up with uniform speed
(d) going down with uniform speed
Tension in the cable = Weight of the elevator
Or, total upward force = total downward force
That is, there's no acceleration or uniform velocity.
So, the elevator is going up/down with uniform speed.
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