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Two identical spheres, each of mass M and negligible radius, are fastened to opposite ends of a rod of negligible mass and lenth 2l. This system is initially at rest with the rod horizontal, and is free to rotate about a frictionless horizontal axis through the center of the rod and perpendicular to the plan of the page. A bug, of mass 3M, lands gently on the sphere on the left, Assume that the size of the bug is small compared to the length of the rod. Express your answesr to all parts of the question in terms of M, L, and physical constants.

A) Determine the Torque about the axis immediately after the bug lands on the sphere

B) Determine the angular acceleration of the rod-sphere-bug system immediately after the bug lands

I got the Torque to be 3Mgl ... which is the right answer, but I dont know where to start for Part B

There is another part to this question...

The rod-sphere-bug system swings about the axis. at the instant that the rod is vertical, determine:

C) the angular speed of the bug

D) the angular momentum of the system

E) the magnitude and direction of the force that must be exerted on the bug by the sphere to keep the bug from being thrown off the sphere.

I have n o clue where to start...

Please help

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# Homework Help: Angular Momentum and torque problem

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