## Trending News

Promoted

# Physics: Circular Motion?

A certain string just breaks when it is under 25 N of tension. A boy uses this string to whirl a 0.75-kg stone in a horizontal circle of radius 2.0 m. The boy continuously increases the speed of the stone. At approximately what speed with the string break?

Please help

### 1 Answer

Relevance

- SlowfingerLv 62 months agoFavorite Answer
Centrifugal force

F = mv²/r

where

m - mass of stone

v - speed

r - radius of circle

Find v such that F exceeds 25N required to break a string

v = √(Fr/m)

v = √(25*2/0.75) = 8.16 m/s

Still have questions? Get your answers by asking now.