8.C) maximum positive workD) NU worn al amA man is lowering a bucket f

1.	8.C) maximum positive workD) NU worn al amA man is lowering a bucket full of water with an acceleration 1m/s2 the work done by him iA) positiveB) negative C) zeroD) infinity
Answer» Let the mass of the bucket be M . => Net force on the bucket = Mg + F = M×a where F is the force applied by the man and a is the net acceleration of the bucket , which , in this case is 1 m/s^2 . => F = M×(1-g) = -ve Work done = F.s = (-ve) × (+ve) = -ve Thus work done by man is negative. [ Note : We have taken downward direction as positive . ]

8.C) maximum positive workD) NU worn al amA man is lowering a bucket full of water with an acceleration 1m/s2 the work done by him iA) positiveB) negative C) zeroD) infinity

Answer»

Let the mass of the bucket be M .

=> Net force on the bucket = Mg + F = M×a where F is the force applied by the man and a is the net acceleration of the bucket , which , in this case is 1 m/s^2 .

=> F = M×(1-g) = -ve

Work done = F.s = (-ve) × (+ve) = -ve

Thus work done by man is negative. [ Note : We have taken downward direction as positive . ]

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8.C) maximum positive workD) NU worn al amA man is lowering a bucket full of water with an acceleration 1m/s2 the work done by him iA) positiveB) negative C) zeroD) infinity

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