Hey guys i have only one question this time on my homework(adsbygoogle = window.adsbygoogle || []).push({});

1) At t=0 a grinding wheel has an angular velocity of 28.0 rad/s. It has a constant angular acceleration of 29.0 rad/s^2 until a circuit breaker trips at time t=2.50s. From then on, it turns through an angle 433rad as it coasts to a stop at constant angular acceleration.

I was able to answer part A which was: Through what total angle did the wheel turn between t=0 and the time it stopped? and figured it to be 594rad but part B is troubling me.

Part B) At what time did it stop?

I tried using: omega_z=omega_oz+alpha*t

to find the speed of the wheel when it intially stops and found it to be 100.5 rad/s Then i tried using: delta_theta=(1/2)(omega_z+omega_oz)*t and moved aroudn this formula to solve for:

t= (2*delta-theta)/(omega_z+omega_oz)

this gave me 11.8 seconds which is wrong....anyone see my problem or have another method to share?

Part c) What was its acceleration as it slowed down?

I hav eno idea how to figure this out but if i had this i think i could solve b easier...any tips?

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# Homework Help: Rotational Motion and acceleration Question

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