trig problem

[emccle]

Here is the problem:

Point P sweeps out central angle theta=2pi/5 as it rotates on a circle of radius r. Find the angular velocity of point P when t=5 sec.

Do I use the formula: w=theta/t ?

Or do I use the formula: s=r*theta?

 

[wjm11]

Point P sweeps out central angle theta=2pi/5 as it rotates on a circle of radius r. Find the angular velocity of point P when t=5 sec.

Your problem statement is unclear. Is "2pi/5" an angle or an angular velocity in radians per second? If it's an angle, how long did it take to "sweep out" this angle? Please state the problem exactly as it appears in the book, including all units. Was there a diagram with additional information?

 

[emccle]

This problem was from a worksheet that my instructor gave us. I gave it to you exactly as it is written on my paper.

 

[wjm11]

Point P sweeps out central angle theta=2pi/5 as it rotates on a circle of radius r. Find the angular velocity of point P when t=5 sec.

Then let's interpret the problem as "Point P sweeps out central angle theta=2pi/5 as it rotates on a circle of radius r in 5 seconds." In that case, use

w=theta/t = (2pi/5)/5 = (2pi/5)(1/5) = 2pi/25 radians per second.

 

[chrisr]

You should examine those formulae to understand the dimensions they give you.

"w" as written represents degrees per second.
"s" is the length of the arc travelled by P in the time given, where theta is measured in radians,
since (2pi)(r) gives the entire circumference.