A stopper tied to the end of a string is swung in a horizontal circle.  If the mass of the stopper is 13.0 g, and the string is 93.0 cm, and the stopper revolves at a constant speed 10 times in 11.8 s,

a.  What is the angular velocity of the stopper?

it goes 2PI*10 radians in 11.8 seconds.

w=20PI/11.8 rad/sec

To find the angular velocity of the stopper, we need to use the formula:

Angular velocity (ω) = 2π * frequency

First, let's find the frequency. We are given that the stopper revolves at a constant speed of 10 times in 11.8 seconds. Therefore, the frequency can be calculated as:

Frequency (f) = number of revolutions / time

In this case, the number of revolutions is 10 and the time is 11.8 seconds. So:

Frequency (f) = 10 / 11.8

Now we can find the angular velocity using the formula:

Angular velocity (ω) = 2π * frequency

Angular velocity (ω) = 2π * (10 / 11.8)

Substituting the numerical values:

Angular velocity (ω) ≈ 2π * (0.847)

Evaluating the expression:

Angular velocity (ω) ≈ 5.33 rad/s

Therefore, the angular velocity of the stopper is approximately 5.33 rad/s.