00:01
Hello everyone, we are going to understand this question here in the question given there is a circular arc which is making theta angle at the center and mass of the wire is m.
00:19
Mass of circular arc is equal to m, mass of circular arc that is m and radius of radius of wire, radius of arc is equal to r and it is making angle at the center, angle at center, theta.
00:59
So, mass density of wire, mass density, lambda is equal to m upon length of arc, that is r into theta.
01:24
Now taking a small part dx partial length of wire partial length of r is equal to d x partial length of arc is equal to d x so we can write d x is equal to r into d theta so mass of partial length, mass of partial length that is equal to lambda into d x.
02:19
Or we can write m upon r d theta knot into r into dx.
02:29
So we can write dm is equal to m upon theta not into d x.
02:38
So, taking the movement of inertia of partial arc about the center of circle, that is represented by d .i, which is equal to d .m into r square.
02:58
R is the radius of circular arc.
03:01
Now, value of d .m, which we have already calculated, that is m upon d -theta into d x into radius is r.
03:14
Now d x is equal to d x is equal to r into d theta.
03:27
So again we can write m upon theta knot into r cube into d theta.
03:45
Now taking the integration this is r cube...