===== Example: Rotational Kinetic Energy when adding objects to the system =====



=== Video ====
Part 1:

You have a rod spinning as depicted in the diagram (in the video). Its length is 2 m and its mass is 10 kg, rotating at a rate of 20 rad/s.

a) What is the rotational kinetic energy of the rod?
{{youtube>gJdKzHawfgE?large}}


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Part 2:

b) A 3 kg mass is attached to the end of the rod. What is the rotational kinetic energy of this system?
{{youtube>BShPtQbG0l0?large}}


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Part 3:

c) Someone throws a sphere (radius = 1 cm, mass = 5 kg) at the other end of the rod, where it sticks and deforms. What is the new moment of inertia?
{{youtube>JanhFQSiZ2o?large}}


=== Four Quadrants ===


{{183_notes:examples:rotation_kinetic_energy_quadrant.png}}