Question

what is the condition of positive work and negative work and zero work and no work in separate​

Answer 1

We know the mathematical expression for work done (W)

W = Force (F) × displacement (s)

Now if either of the dependent quantities of work is zero, then the work done on the system will be 0.

Suppose a body is moving with some velocity and a force is applied in the direction opposite to the motion of the body in order to stop it, then we say that the body will experience a negative work as the direction of velocity and force are opposite and as per sign convention we assume force as a negative quantity in the given case.

Also we consider work done to be negative when a body does any work or when work is done by the system or body.

When the work is done on the system or body we consider work done to be positive or when the applied force on a system is positive.        

Answer 2

Answer: negative work - if angle between direction of force applied and direction of motion is more than 90°

positive work if angle is less than 90°

zero work if angle is 90°