# Rotational kinematics question

#### Leid_X09

A coin with a diameter of 1.50 cm is dropped on edge onto a horizontal surface. The coin starts out with an initial angular speed of 13.4 rad/s and rolls in a straight line without slipping. If the rotation slows with an angular acceleration of magnitude 2.03 rad/s2, how far does the coin roll before coming to rest?

I know that wf^2 = wi^2 + 2a(dTheta) should be used, and I find theta to be 44.2 but the 44.2 is in rads, so how do i translate this into ms? What does the 1.50 diameter have to do with this problem?

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#### LowlyPion

Homework Helper
A coin with a diameter of 1.50 cm is dropped on edge onto a horizontal surface. The coin starts out with an initial angular speed of 13.4 rad/s and rolls in a straight line without slipping. If the rotation slows with an angular acceleration of magnitude 2.03 rad/s2, how far does the coin roll before coming to rest?

I know that wf^2 = wi^2 + 2a(dTheta) should be used, and I find theta to be 44.2 but the 44.2 is in rads, so how do i translate this into ms? What does the 1.50 diameter have to do with this problem?
How many radians to one revolution?

What distance is that? Maybe think circumference plays a part?

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