00:01
Hello and welcome to this video solution of numerate.
00:04
Here it's given that there is a one meter length of string that is wrapped around a solid disk right.
00:10
So the length is one meter and the disk is having a mass of 0 .25 kgs.
00:18
It is having a radius r which is 0 .3 meters right.
00:23
The string is pulled by a force f which is 20 newton.
00:26
Now based on this you have to calculate the angular velocity of the disk after the string is pulled off right.
00:33
Now what you need to do is first you need to calculate theta which is the angular displacement of the disk that is covering a linear length of one meter.
00:42
So it's l by r right.
00:45
1 by r is 0 .3 right.
00:48
This will be in radians or it's 10 by 3 radians we can write.
00:55
Next what you need to do is you need to calculate the angular acceleration from the torque equation.
01:00
So tau, the torque produced will be equal to the moment of inertia times angular acceleration.
01:05
So this torque will be nothing but the force times the radius because r is the line of action of the force right.
01:14
So here there's a force f so r will be line of action from the center right of rotation...