PhysicsBowl 2017 Q18

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PhysicsBowl 2017

18) This problem involves the angular kinematics of a disk that comes to rest in 2.5 seconds. The disk decelerates to rest in 2.5 seconds. We can start the question by drawing out this situation.

Where t is time, θ is angular displacement, and ω is angular velocity

We can take a look at the kinematic equations adapted for angular motion.

Where t is time, θ is angular displacement, ω is angular velocity, and α is the angular acceleration

Considering the values we have, and that we need to solve for ω[i], we will use the first equation to do so.

Where t is time, θ is angular displacement, and ω is angular velocity

Answer: E