Kinetic Energy Of an rotating object

AI Thread Summary
To calculate the kinetic energy of a rotating object, the moment of inertia must first be determined. The kinetic energy formula for rotation is given by 1/2 I ω², where I is the moment of inertia and ω is the angular velocity in radians per second. For a phonograph album, the moment of inertia can be calculated based on its mass and diameter. The discussion highlights the need to convert the album's rotation speed from RPM to radians per second for accurate calculations. Understanding these principles is essential for solving the kinetic energy problem effectively.
Duely Cack
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1. A 75-g phonograph album of 30-cm diameter spins at 33.3 rpm. What is its kinetic energy?
 
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Duely Cack said:
1. A 75-g phonograph album of 30-cm diameter spins at 33.3 rpm. What is its kinetic energy?

Welcome to PF.

What are your thoughts on how to go about solving it.
 
well i think that Kinetic Energy is 1/2mv2so is it like that but instead of v you put in the 33.3 rpm. like 1/2(75)(33.3)2 maybe?
 
Duely Cack said:
well i think that Kinetic Energy is 1/2mv2so is it like that but instead of v you put in the 33.3 rpm. like 1/2(75)(33.3)2 maybe?

What is the moment of inertia of the phonograph?

Using the moment of inertia what is the formula then for rotational kinetic energy?
 

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