00:01
Hello everyone, we are going to understand this question here given in the question.
00:10
Length of row, length of row that is represented by l, which is 5 meter.
00:26
Mass of row, mass of row that is represented by small m, which is 30 kg.
00:42
And height of building, height of building, that is represent.
00:55
By h which is 10 meter.
01:04
Now we have to find the work done or energy required to pull the string at the top of the building.
01:14
So here it is given center of rope.
01:17
Sorry, we know that center of mass of rope is equal to center of mass of rope.
01:32
That is at l by 2.
01:36
Value of l is 5 upon now, mass density of rod, sorry, mass density of string or mass density of rope, mass density of rope, that is m upon l.
02:10
So mass of small part of rope, mass of partial rope, that is represented by dm, which is m upon l into d x so when we are pulling this string in this rope in upward so work done is equal to change in potential energy it means dm into g into x so dm is m upon l into d x into dm is sorry, this is represented by dw.
03:13
Now taking integration of both sides.
03:19
Now taking integration, taking integration...