Question

Name the type of work with the one example of each. ​

Answer 1

$\bf \huge \mathfrak{ \underline{ \underline \pink{Answer}}}$

1. Positive Work : If a force displaces the object in its direction, then the work done is positive. The example of this kind of work done is motion of ball falling towards ground where displacement of ball is in the direction of force of gravity.

2. Negative Work : If the force and the displacement are in opposite directions, then the work is said to be negative. For example if a ball is thrown in upwards direction, its displacement would be in upwards direction but the force due to earths gravity is in the downward direction.

3. Zero Work : If the directions of force and the displacement are perpendicular to each other, the work done by the force on the object is zero.

For example, when we push hard against a wall, the force we are exerting on the wall does no work, because in this case the displacement of the wall is d = 0. However, in this process, our muscles are using our internal energy and as a result we get tired.

Answer 2

Different Types Of Work

Work is defined as the force acting on a body which is responsible for the displacement of the body. Work is measured as a constant force and is the dot product of force and displacement.

W = F.S.cosq

Where,

F is the force

S is the displacement

q is the angle between F and S

Work is a scalar quantity and is the product of two vector quantities. Depending on the value of q, there are three types of work:

• When q = 0°, work is said to be positive. Stretching of the spring is an example of positive work as the force is acting in the direction of displacement of the spring.
• When q = 180°, work is said to be negative. The frictional force is an example of negative work as the force is acting in the opposite direction.
• When q = 90°, work is said to be zero. For a body moving a circular path with a centripetal force acting on it with zero speed, the force will be at the right angle