Two thin rods of length L are rotating with the same angular speed ω (in rad/s) about axes that pass perpendicularly through one end. Rod A is massless but has a particle of mass 0.64 kg attached to its free end. Rod B has a mass of 0.64 kg, which is distributed uniformly along its length. The length of each rod is 0.70 m, and the angular speed is 5.8 rad/s. Find the kinetic energies of rod A with its attached particle and of rod B.
Can you explain to me how this is done?
Thank you!
Can you explain to me how this is done?
Thank you!
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This is a moment of inertia problem
First look up the moment of inertia of a thin rod about an axis through one end (http://en.wikipedia.org/wiki/List_of_mom…
Then look up the moment of inertia of a particle about an axis some distance from it
(same source)
Recall that Ek of an object in circular motion is 1/2 * I * w^2, where I is the moment of inertia and w is the angular speed.
Calculate the separate Ek's
First look up the moment of inertia of a thin rod about an axis through one end (http://en.wikipedia.org/wiki/List_of_mom…
Then look up the moment of inertia of a particle about an axis some distance from it
(same source)
Recall that Ek of an object in circular motion is 1/2 * I * w^2, where I is the moment of inertia and w is the angular speed.
Calculate the separate Ek's