Angular Velocity of weighted plates

AI Thread Summary
To find the angular velocity of the two combined plates, apply the principle of conservation of angular momentum. Initially, the first plate has angular momentum due to its rotation, while the second plate has none as it is stationary. When the second plate is dropped onto the first, the total angular momentum before the collision must equal the total angular momentum after. The combined angular velocity can be calculated using the formula for angular momentum, considering both plates' mass and radius. Understanding this concept is crucial for solving the problem effectively.
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Homework Statement



A 7kg plate with a radius of 1.4m is rotating at 63 rad/s around an axis perpendicular to its center. Another plate that is not rotating is dropped onto the first plate and their centers align. The second plate is 5kg, with a radius of .8m. What is the angular velocity of the two disks combined?


Homework Equations





The Attempt at a Solution



I am really confused with this problem.
What is my first step?

Thanks
 
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randomss444 said:

Homework Statement



A 7kg plate with a radius of 1.4m is rotating at 63 rad/s around an axis perpendicular to its center. Another plate that is not rotating is dropped onto the first plate and their centers align. The second plate is 5kg, with a radius of .8m. What is the angular velocity of the two disks combined?


Homework Equations





The Attempt at a Solution



I am really confused with this problem.
What is my first step?

Thanks

Has your class been discussing the conservation of angular momentum?
 

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