# A ball of mass 300 gram is whirled on the end of a string in a horizontal circle of radius r = 0.450 m at a constant?

A ball of mass 300 gram is whirled on the end of a string in a horizontal circle of radius

r = 0.450 m at a constant speed. If angle 25.0= , the speed of the ball is??

The answer is 1.43m/s but I don't know how to solve this.

### 2 Answers

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- WhomeLv 78 months agoFavorite Answer
What is the reference frame for the angle?

I'll assume that it is measured from vertical

tanθ = (v²/r) / g = v² / rg

v² = rgtanθ

v² = 0.450(9.81)tan25

v² = 2.0585

v = 1.43 m/s

- Anonymous8 months ago
tan 25° = 0.466 = g/(V^2/(L*cos 25))

0.466*V^2 = 9.8*0.906*0.45

V = √9.8*0.906*0.45 / 0.466 = 2.92 m/sec...quite different from yours

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