A cylinder has inner and outer radii of #12 cm# and #15 cm#, respectively, and a mass of #4 kg#. If the cylinder's frequency of rotation about its center changes from #5 Hz# to #8 Hz#, by how much does its angular momentum change?

1 Answer
Mar 28, 2016

Answer:

#"change of angular momentum="0,4428*pi#

Explanation:

#"change of angular momentum="I*Delta omega#
#I:"moment of inertia"#
#Delta omega:"change of angular velocity"#
#I=1/2*m*(a^2+b^2)"cylinder axis at center"#
#m:4 kg#
#a=12 cm=0,12 m#
#b=15 cm=0,15 m#
#I=1/ cancel(2)* cancel(4) ((0,12)^2+(0,15)^2)#
#I=2*(0,0144+0,0225)#
#I=2*0,0369#
#I=0,0738#
#Delta omega=omega_2-omega_1#
#Delta omega=2*pi*f_2-2*pi*f_1#
#Delta omega=2*pi(f_2-f_1)#
#f_1=5 Hz" "f_2=8 Hz#
#Delta omega=2*pi(8-5)#
#Delta omega=6*pi#

#"change of angular momentum="0,0738*6*pi#
#"change of angular momentum="0,4428*pi#