Question

Justify giving proper reasoning whether the work done in the following cases is positive or negative :
(i) Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket.
(ii) Work done by gravitational force in the above case.
(iii) Work done by friction on a body sliding down an inclined plane.
(iv) Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity.
(v) Work done by resistive force of air on a vibrating pendulum in bringing it to rest.
​

Answer 1

Answer:

1- positive

2- negative

3- negative

4-

5- negative