- #1

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- Homework Statement
- A wheel 2.00 m in diameter lies in a vertical plane and rotates with a constant angular acceleration of 4.00 rad/s^2. The wheel starts at rest at t= 0, and the radius vector of point P on the rim makes an angle of 57.3° with the horizontal at this time. At t = 2.00 s, find

(b) the linear speedand acceleration of the point P

- Relevant Equations
- v=r##w##

ar=r##w##^2

at=r*alpha

v=1.00*8=>v=8 rad/s

ar=>100*8^2=>ar=64 rad/s^2

at=1.00*4=>at=4 rad/s^2

The only question I have is ar=-64 rad/s^2, not 64 rad/s^2 as I calculated. I believe this is because the wheel is accelerating in a clockwise direction. However this is not indicated by the mathematical equation. How do I detect that the acceleration is clockwise?

ar=>100*8^2=>ar=64 rad/s^2

at=1.00*4=>at=4 rad/s^2

The only question I have is ar=-64 rad/s^2, not 64 rad/s^2 as I calculated. I believe this is because the wheel is accelerating in a clockwise direction. However this is not indicated by the mathematical equation. How do I detect that the acceleration is clockwise?

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