00:01
Hi, welcome to the solution of problem number 109.
00:06
Consider a circular motion.
00:12
Here, the speed is constant.
00:19
Now, this is the most important point.
00:21
Speed is constant does not mean that velocity is constant.
00:31
Why? because speed is constant means the magnitude.
00:38
Of velocity is constant.
00:42
That is true, but the direction is not constant.
00:55
Because if in this point, arbitrary point a, the velocity is in this direction, in this arbitrary point b, the velocity will be in this direction.
01:08
In this arbitrary point c, the velocity will be in this direction.
01:11
And so on.
01:14
So speed is constant does not mean the velocity is constant.
01:22
Now for a circular motion to happen, there should be a centripetal force.
01:30
A centripetal force should be there.
01:35
Now, now there is a centripetal force.
01:45
Let us call it f c.
01:48
It is there...