What's the mistake here @pratyaksh_tyagi bro ?
In your solution the limits are not correct
You need to integrate from l to l/2
Think about what is x here. L/2 and L/4 are the heights of the apparent concentration of the hanging masses
For the first pic Q.7 - A ?
For the second pic 17th question Ans : D ?
It is given b for 7 question and a for 17th
Okay tell me first what is x @Prakhar_Gupta
X I took it to be the height of com of the rope.
So 2x would be the length.
Got it for 17th.
Yeah so initially 2x will be l and finally 2x will be l/2
So x goes from l/2 to L/4
Okay but what about that differential factor ?
Let's say the rope will go down by a distance dx so now the height of the COM changes by a distance dx/2
Also can you show the Working of Q.17 @Prakhar_Gupta
I have assumed x as the height of com. so dx would mean displacement of com in downward direction.
It seems that considering change in potential energy is a better approach
Q 17 is already solved by pratyaksh in post #4.