00:02
In the first part of this problem, we have to show that the force acting on pendulum is same as the force in the hooks law.
00:08
So we have to show that the force acting on pendulum that is proportional to the displacement, that is x.
00:16
And this force is directed towards the main position.
00:21
So we have to show this relation for the case of simple pandolin.
00:25
Let's draw the simple pendulum first.
00:29
So this is the simple pendulum, whose component of force mg sine fendulum.
00:35
Is responsible to execute the simple harmonic motion and this force is directed towards the mean position which is represented by this o.
00:44
So we can write here this force f should be equals to minus mg sign of theta.
00:53
Now using the small angle approximation which is a sign of theta is approximately equals to theta when theta is very small then this square will be f is equal to minus m g theta now taking this this a say this is a oh a and say this is c as a semicircle we can write here an expression for the this circumference which is represented by this x as a theta is equals to x divided by and where this l is the length of the pendulum then this equation will be f is equal to minus m g x divided by l so this can be further written as minus into mg divided by l into x we know that this is mg divided by l this is the constant so we can white f is proportional to minus x so this is the form of the hook slah which is also applicable for the simple pandolo and proved...