Angular Acceleration: Propellor on Boat Increases from 50 to 150 rev/min

AI Thread Summary
The problem involves calculating the angular acceleration of a boat's propeller that accelerates from 50 rev/min to 150 rev/min in 2.5 seconds. The initial and final speeds have been converted to radians per second, which is a necessary step. Kinematic equations used for linear motion with constant acceleration can also be applied to rotational dynamics. The key is to find the change in angular speed over the time interval. Understanding the relationship between linear and rotational motion can clarify the approach to solving the problem.
petal5
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The problem is:

The angular speed of a propellor on a boat increases with constant acceleration from 50 rev/min to 150rev/min in 2.5s.What is the angular acceleration of the propellor?

I'm not sure how to go about the problem.So far I've converted the 50rev/min and the 150rev/min to rad/s.Do I have to work out wf-wi and tf-ti or am I going about it wrong?
Thanks!
 
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petal5 said:
Do I have to work out wf-wi and tf-ti or am I going about it wrong?
Sounds like you are on the right track.
 
Kinematic equations can be applied to translational motion with constant acceleration. The same works in rotational dynamics. In fact, the equations for both types of motion share a common format with different variables. Given an initial and final angular speed during some time interval, what is the acceleration? If you're still unsure, ask yourself, "How would I solve if the variables were dimensionally linear?" Is there a similar rotational equivalent?
 
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