Physics Angular Momentum
posted by jhay
A bullet with a mass m = 4.83 g and initial speed of 330 m/s passes through a wheel which is initially at rest as in the gure. The wheel is a solid disk with mass M = 2.29 kg and radius R = 18.6 cm The wheel rotates freely about an axis through its center and out of the plane shown in the gure. The bullet passes through the wheel at a perpendicular distance 14.8 cm from the center. After passing through the wheel it has a speed of 201 m/s.
1) What is the angular speed (rad/s) of the wheel just after the bullet leaves it?
2) How much kinetic energy (J) was lost in the collision?

Damon
Initial angular momentum of bullet around axis of wheel = I w = m r^2 w = m r v = .00483 * .148 * 330 = .2359
Final angular momentum of bullet around axis of wheel = .00483 * .148 * 201 = .1437
change in angular momentum of bullet = .2359  .1437 = .0922
that is the angular momentum of the wheel
I w = .0922
I = (1/2) M R^2 =.5*2.29*.186^2 = .03961
so
w = .0922/.03961 = 2.328 rad/s
Ke original = (1/2) m v^2 of bullet
Ke final =(1/2)mvfinal^2 of bullet + (1/2)I w^2 of wheel 
jhay
Awesome!
Thanks a bunch
Respond to this Question
Similar Questions

Physics
A bullet with a mass m = 4:83 g and initial speed of 330 m/s passes through a wheel which is initially at rest as in the The wheel is a solid disk with mass M = 2.29 kg and radius R = 1.:6 cm. The wheel rotates freely about an axis … 
Physics
A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration … 
PHYSICS
A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration … 
Physics
A rotating uniformdensity disk of radius 0.7 m is mounted in the vertical plane. The axle is held up by supports that are not shown, and the disk is free to rotate on the nearly frictionless axle. The disk has mass 5 kg. A lump of … 
physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 260 N applied to its edge causes the wheel to have an angular acceleration … 
physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 250 N applied to its edge causes the wheel to have an angular acceleration … 
Physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 300 N applied to its edge causes the wheel to have an angular acceleration … 
Physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 200 N applied to its edge causes the wheel to have an angular acceleration … 
physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 280 N applied to its edge causes the wheel to have an angular acceleration … 
physics
A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 270 N applied to its edge causes the wheel to have an angular acceleration …