Question

A potter's wheel (a solid, uniform disk) of mass 6.0kg and radius 25cm spins about its central axis with an angular speed of the wheel is 15rpm. A 0.50kg lump of clay is moving with a tangential velocity of 2m/s hits the wheel and sticks at the edge. Find the new angular speed of the system.

Answer 1

okay you need to apply the concept of angular momentum conservation
so Li=Lf
where L is angular momentum of the system
i prefer to work with equations in such questions
Li=initial angular momentum =\[mr ^{2}/2 \times \omega \]
finally the moment of inertia of the system becomes
moment of inertia of disc + moment of inertia of the lump of clay
now substitute the masses of the objects of the system in the respective moments of inertia
you'll get the initial moment of inertia of the system=(6r^2)/2
and the final as (7r^2)/2
so if we apply angular momentum conservation,
we get
(6r^2)/2 x 15 = (7r^2)/2 x final angular velocity
so we get the final angular velocity nearly 12.8 rpm
if you did not get anny point of this answer, feel free to aask