Question

define work. in hich case is the work done positive, zero or negative ​

Answer 1

Work :-

Work done in moving a body is equal to the product of force and the displacement of the body in the direction of force.

Example :-

When an engine applies force on a train. The train moves. So, work is said to be done by the engine.

➞ Work = Force × Displacement

➞ W = F × s

Unit of Work :-

The SI unit of work is joule. It is denoted by the letter J.

• Work is a scalar quantity.

Positive work done :-

• Work done is positive when a force acts in the direction of motion of the body.

Negative work done :-

• Work done is negative when a force acts opposite to the direction of motion of the body.

Zero work done :-

• Work done is zero when a force acts at right angles to the direction of motion of the body.

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