Solid Ball Problem: Kinetic Energy Calculation

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To calculate the kinetic energy of a solid ball rotating about its diameter, the correct formula is KE = 1/2 * I * ω^2, where I is the moment of inertia. For a solid sphere, the moment of inertia is I = 2/5 * m * r^2, not 1/2 * m * r^2. Ensure that mass is in kilograms, diameter is converted to meters, and angular velocity is in radians per second. Common errors include incorrect unit conversions and using the wrong formula for moment of inertia. Double-check calculations and consider seeking assistance if issues persist.
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Here is my last problem I am having problems with:
A solid ball of mass 1.70kg and diameter 16.0cm is rotating about its diameter at 65.0rev/min. What is its kinetic energy ?
Ok so KE for rotation is : 1/2*I *w^2
so I found I with m *r2
and then plugged everything into the Ke equation but didnt get it right. I converted everything and divided the diameter by 2. What could I be doing wrong??
 
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There are a few things that could be causing an error in your calculation. First, make sure you are using the correct units for all values. Mass should be in kilograms, diameter in meters, and angular velocity in radians per second. Also, double check that you are using the correct formula for moment of inertia (I = 1/2 * m * r^2) and that you are using the correct value for the radius (in this case, half of the diameter). It's possible that you may have made a small error in your calculations or used the wrong values. I would recommend double checking your work and if you're still having trouble, try approaching the problem from a different angle or asking for help from a classmate or teacher.
 
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