An pie plate of radius 0.12 m spins and accelerates at a constant rate of 13 rad/s. What was its angular acceleration?

R=0.12. W1=13 W2=29 t=5.4
(29 -13) /5.4= 2.96rad/s is the answer I calc but the answer key had 2.8 rad/s

To calculate the angular acceleration, we can use the formula:

Angular acceleration (α) = (final angular velocity - initial angular velocity) / time

In this case, the initial angular velocity (W1) is given as 13 rad/s, the final angular velocity (W2) is given as 29 rad/s, and the time (t) is given as 5.4 seconds.

Plugging in the values into the formula:

α = (29 rad/s - 13 rad/s) / 5.4 s
α = 16 rad/s / 5.4 s
α ≈ 2.963 rad/s²

So, the calculated angular acceleration is approximately 2.963 rad/s².

You mentioned that the answer key stated 2.8 rad/s. It is possible that the answer key rounded off the value to one decimal place. In that case, the rounded value would indeed be 2.8 rad/s. However, the exact calculation yields a value of 2.963 rad/s², which has more precision.