What is the angular displacement of a thrown ball

[ashezb]

Homework Statement

A ball is thrown to a man and reaches him in 60s. The ball curves because it is spinning at an average angular velocity of 330 rev/min on its way to the man's hands. What is the angular displacement of the ball

Homework Equations

θ=ωt

The Attempt at a Solution

I converted 330 rev/min to 17.279 rad/s
but when I plug it into the equation I get 1,036.74... I feel like I'm missing a final step here but I don't know what I'm doing wrong.. please help

 

[TSny]

Hello, ashezb. Welcome to PF!

Are you sure the time is 60s? That's one heck of a throwing arm

Your conversion of 330 rev/min to rad/s does not look correct. Remember, there are $2\pi$ radians in one revolution.

 

[gneill]

Homework Statement

A ball is thrown to a man and reaches him in 60s. The ball curves because it is spinning at an average angular velocity of 330 rev/min on its way to the man's hands. What is the angular displacement of the ball

Homework Equations

θ=ωt

The Attempt at a Solution

I converted 330 rev/min to 17.279 rad/s
but when I plug it into the equation I get 1,036.74... I feel like I'm missing a final step here but I don't know what I'm doing wrong.. please help

Hi ashezb, Welcome to Physics Forums.

How did you convert 330 rpm to radians per second? Can you write it out? (I ask because your value doesn't look right).

Once you have the total angular distance, remember that the displacement should lie in the range 0 → $2\pi$. How might you go about reducing (normalizing) the angle?

 

[ashezb]

Now that I really think about it 60s is one heck of a throw, but the question does say 60s

Yes I did my conversion wrong. I used π in stead of 2π

but I am still confused...these are the given answers
a) 21 rad
b) 20 rad
c) 19 rad
d) 17 rad
e) 14 rad

The only way I can make is work is to turn the seconds into 0.60 seconds in which case a would be correct.

Thanx for being so welcoming and so helpful :)

 

[TSny]

The only way I can make is work is to turn the seconds into 0.60 seconds in which case a would be correct.

Sounds good.