Rotational Energy of 3 Point Masses along a Rigid Rod

[shenwei1988]

Three point masses lie along a rigid, massless rod of length L = 5.61 m :

- Two particles, both of mass m = 2.1 kg, lie on opposite ends of the rod.
- Mass M = 7.29 kg is in the center of the rod.

Assume the rod lies along the x-axis, and rotates about the y-axis. about a point 1.28 m from one end at constant angular speed ω = 5.38 rad/s.

Find the kinetic energy of this system



could someone explain the ( about a point 1.28m from one end) . dose the distance 1.28 contribute any Kinetic energy to the system?
thank you so much

 

[Doc Al]

Use the distance from the axis of rotation and the angular speed to find the linear speed of each point mass. Use that to find their kinetic energy.