Encyclopedia of Science

[shawnbart35]

A wheel is rotating at 9 rad/s and has a constant acceleration of 0.5 rad/s/s for 30 seconds.Find

a)The angular velocity after the 30 seconds
b)The angle turned through by the wheel in the 30 seconds in both radians and degrees

PLZ CAN ANYONE HELP ME WITH THIS PROBLEM THANX.

[CynthiaA]

[quote="shawnbart35"]A wheel is rotating at 9 rad/s and has a constant acceleration of 0.5 rad/s/s for 30 seconds.Find

a)The angular velocity after the 30 seconds
b)The angle turned through by the wheel in the 30 seconds in both radians and degrees

PLZ CAN ANYONE HELP ME WITH THIS PROBLEM THANX.[/quote]

I think this is trig, which I have not learned yet. I did work the problem, but have no way of truly knowing if I am correct or not because I have not truly learned trig. So maybe someone will come along who has been formaly taught trig and will help us out with this. It would be interesting to see if I came up with the correct answers.

CynthiaA

[timmy]

Note that no trig knowledge is needed here.

a)
The initial angular velocity w[size=9]0[/size] is 9 rad/s, then the angular velocity w after 30 seconds can be found by
w = w[size=9]0[/size] + at
where a is the constant angular acceleration, and t is the duration of the acceleration.

So
w = 9 + 0.5*30 = 24 rad/s

b)
The angle turned (theta) can be found by the formula
theta = w[size=9]0[/size]t + 0.5at^2

So
theta = 9*30 + 0.5*0.5*30^2
= 495 rad


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