00:01
The kinetic energy of a rotating object is given by the expression k equals half i omega square here k is the kinetic energy i is the moment of inertia and omega is the angular speed now for rod a which is massless with a particle at its free end the moment of inertia is given by m l square.
00:57
Here, m is the mass of the particle which is 0 .62 kilogram and l is the length of rod a which is given to be 0 .81 meter.
01:10
Now substituting i in the expression for k, we get half into ml square multiplied by omega square.
01:20
And the angular speed of the rod is given to be 4 .5 radian per second square.
01:29
Sorry, radian per second.
01:32
Now, on substituting the values, we get half into 0 .62 kilogram multiplied by 0 .81 meter the whole square, multiplied by 4 .5 radian per second, the whole square.
01:47
On calculating we get 4 .1186 joules.
01:53
Rounding this to two significant figures we get 4 .1 joules.
01:58
Now for the case of rod b, the moment of inertia about its end is given by the expression 1 by 3 mr l square...