WORK

Work is a process by which displacement generate in any object by applying a force on it.
It is the scalar product of force and displacement.
If 'd' displacement generated by force 'F' then the total work done -
W = F.d = Fd Cosθ
here θ is the angle formed between force and displacement.

• If θ is 0 means force and displacement in same direction then the work  W = Fd (maximum)  (cos0=1).
• If θ is 90 means force and displacement perpendicular to each other then the work  W =0 (minimum) (cos90=0).

• If there is no any displacement by force the applied work done 'zero'. Like a person pushing a wall.

• In a circular motion total work done is zero because there is no any displacement in circular path.
• Its unit is Newton*meter = joule  (N.m = J).
• 1J = 1N.1m 
• When one newton force applied on a body and it displaced by one meter then the work done is one joule.
• Dimension is [M^1L^2T^-2].
• In the form of derivative  dW = F.ds = FdS Cosθ.