Question

Define the term work. Name and define SI unit of work.
Give the sign of the work done by the force in the following case with
explanation. (i) Work done by gravitational force in lifting a bucket
out of a well by means of a rope tied to the bucket.
(ii) Work done by an applied force on a body moving on a rough
horizontal plane with uniform velocity

Answer 1

Answer:

work is nothing but = force × displacement

and work done can be defined as the force us applied on an object and the object is displaced in the direction of force .

Answer 2

Answer:

Work

when the body undergoes displacement in the direction of force or in the direction of component of force .

S I Units

Joule

Work done by the gravitational force in lifting a bucket from the well is negative

Explanation:

Because bucket is lifting in the opposite direction to gravitational force . So gravitational force is negative.

Work done by the applied force on a body moving in a rough horizontal plane with uniform velocity is positive.

Explanation:

Because when we apply the force on the object it moves in the direction of applied force . So it is positive