Physik-1

In this section,we will study about rod in a particular case,let's suppose rod is in a vertical direction with respect to the ground.Now Rod is held,but it is released from rest and falls on the ground making parallel axis with the ground.

Now,We have to consider a brief moment of time when that rod was falling,when rod made an angle with the ground.Let's say that angle at any time t be Φ.Now,it is clear that the rod during falling will make multiple angles with multiple time intervals,so we just took one such moment,also duration of the existence of this angle will be very short as rod falls quickly to the ground,due to the special gravity.

Now,Let's say the Mass of uniform rod be M and length of uniform rod be L,so if we imagine in mind,a imaginary triangle will be created whose hypotenuse is of course L,now the other two length's are unknown,while we have angle information which is Φ,so with this angle we can calculate or let's say measure the other lengths,thanks to power of trigonometry,by using science of trigonometry,other unknown measurements will be visible to the naked eye.

First let's say height of imaginary triangle be H and base of imaginary triangle for that specific case,which exists for short period be B.

Now ,by using trigonometry on height with hypotenuse,we have

Sin Φ =H/L

H = L.SinΦ

So,again applying trigonometry on base of imaginary triangle and length of rod,we have

Cos Φ = B/L

B = L.cosΦ

Now,also lengths are calculated.Now,concept of centre of mass,which is a hypothetical point ,where all mass is said to be concentrated,in reality it's wrong,but in science it exists,so this centre of mass for rod will be at of course centre.

Now, let's say rod FG of Length L and centre of mass is at hypithetical point O,then

FO=L/2=OG=GO