Basics of work done
A trip to the market
On Sunday, Ram’s father asked him to lift the water can and stand for 5 minutes
Obeying him, Ram lifted it for 5 minutes and stayed there.
Ram exclaimed how much he worked but to his surprise his father said that he did no work at all !!
Ram was confused, and could not understand why his father was saying so
So, he asked his father to explain the reason behind this remark
Let’s see what did Ram come to know about work
By intuition we know that we do work when we move something from its position
The scientific definition of work is also similar to this, let’s see what science says about work
Work is said to be done when "applied force produces displacement in the direction of force"
This means, we need two parameters to define amount of work done
We need the amount of applied force
And we need the displacement
Together these parameters give work done as above
So, amount of work done is given by above relation
The SI unit of work is Joule (J)
The SI units of force and displacement are Newton(N) and meter(m) respectively
This means that if 1 N of applied force produces a displacement of 1 m then 1 J of work is said to be done
One thing to be noticed is that displacement is essential for work to be done
Although a body may travel some distance, but it’s displacement may or may not be zero
In case the starting and final positions of a body are the same, then displacement is zero
So, work done is also zero !!
Also, if in case a force is applied but no displacement occurs
Then also NO work is done !!
Work is said to be done when applied force produces displacement in the direction of force applied
Work done is the product of force applied and displacement of the body
If either any one parameter is zero, then work done turns out to be zero
Work done always requires displacement and NOT distance covered by the body