# What is the tension in the string at the bottom position (magnitude only)?

A 2.2kg object is whirled in a vertical circle whose radius is 1.0m. The object makes 5 complete circles in a time of 4.5s. What is the tension in the string at the bottom position (magnitude only)?

### 1 Answer

Relevance

- billrussell42Lv 72 months agoFavorite Answer
tension equals centripetal force plus weight

ω = 5 circles/4.5 s x 2π rad/circle = (10/4.5)π rad/s

T = mrω² + mg = (2.2)(1)((10/4.5)π)² + (2.2)(9.8) = 129 NCentripetal force f = mV²/r = mrω² ω is angular velocity in radians/sec 1 radian/sec = 9.55 rev/min m is mass in kg r is radius of circle in meters V is the tangental velocity in m/s = ωr f is in Newtons

Still have questions? Get your answers by asking now.