Posted by robert on Tuesday, November 13, 2007 at 5:02pm.
A ball rolls along a circle whose radius is 2 ft. How far does the ball roll if it goes around the circle 12.5 times?
I got 25 ft as my answer. I just multiplied the two numbers and I got 25. Is this right?

math  bobpursley, Tuesday, November 13, 2007 at 5:04pm
Nope. The distance around the circle is PI*4.
PI*4*12.5= ? way over 25. Way over 100, but not over 200

math  robert, Tuesday, November 13, 2007 at 5:07pm
is it 157.1?

math  Ms. Sue, Tuesday, November 13, 2007 at 5:12pm
I got 157 feet.

math  robert, Tuesday, November 13, 2007 at 5:15pm
how did you get that?

math  Ms. Sue, Tuesday, November 13, 2007 at 5:06pm
Oops. I assume the ball is rolling around the circumference of the circle, not the radius.
To find the circumference of the circle, use this formula, in which C = circumference, r = radius, and pi  3.14
C = 2r * pi
C = 4 * 3.14
C = ?
Now multiply 12.5 by the circumference.
If you post your answer we'll check it. You can also study about the circumference at this site.
http://www.mathgoodies.com/lessons/vol2/circumference.html
Answer This Question
Related Questions
 physics  a child is twirling a 0.0120 kg ball on a string in a horizontal ...
 physics  A child is twirling a 0.0165kg ball on a string in a horizontal ...
 Physics  A tennis ball connected to a string is spun around in a vertical, ...
 Physics  A tennis ball connected to a string is spun around in a vertical, ...
 Physics  A ball rolls down an incline at a constant acceleration of 2 m/s^2. ...
 physics  A child is twirling a 0.0100 kg ball on a string in a horizontal ...
 Physics  A ball on the end of a string travels in a horizontal circle at a ...
 Physics  A child is twirling a 0.0120kg plastic ball on a string in a ...
 Physics  A pitcher hurls a 0.25kg ball around a vertical circular path of ...
 Physics  A child twirling a 0.0120kg ball on a string in a horizontal circle ...
More Related Questions