A solid disk, spinning counter-clockwise, has a mass of #6 kg# and a radius of #2 m#. If a point on the edge of the disk is moving at #5/2 m/s# in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?

1 Answer
Jan 14, 2018

Answer:

#omega = 1.25 (radians/s)# and #L = 15 (kg*m^2)/s#

Explanation:

The relationship between instantaneous velocity, v and angular velocity, #omega#, is
#omega = v/r#

So #omega = (5/2 m/s)/(2 m) = 1.25 (radians)/s#

Angular momentum is #I*omega# where
#I = (M*R^2)/2#

So, the angular momentum, #L#, is
#L = (6 kg*(2 m)^2)/2*1.25 (radians)/s = 15 (kg*m^2)/s#

I hope this helps,
Steve