physics help?

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A 0.40 kg ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.2 m on a frictionless horizontal surface. The cord will break when the tension in it exceeds 61 N.

(a) What is the maximum speed the ball can have?

(b) How would your answer be affected if there were friction?

2007-12-15 07:21:07 · 1 answers · asked by Daydreamer 3 in Science & Mathematics ➔ Physics

1 answers

The force required to keep the ball moving in a circle is

mv² / r

This force is provided by the tension in the cord, which has a breaking point of 61 N, so

61 N = mv² / r

Plug in the mass and the radius to find the unknown velocity. Friction will have no effect as that force is always perpendicular to the centripetal force.

2007-12-15 07:43:21 · answer #1 · answered by jgoulden 7 · 0⤊ 0⤋