# Circular Motion of a bead

1. Feb 28, 2005

### kidia

A small bead with a mass of 100grams slides along a semicircular wire with a radius of 10 centimeters that rotates about a vertical axis at a rate of 2 revolutions per second.Find the value of angle p for which the bead will remain stationary with respect to rotating wire.

Any idea on this?

2. Feb 28, 2005

### ramollari

The whole problem is to find the angle which the line joining the bead and the centre of the semicircle makes with the horizontal.
The solution is to solve a resulting equation either for $$\theta$$ or for r. Consider vertical equilibrium first to deduce the vertical component of the normal force. Then, consider the horizontal forces and acceleration at a given time to solve for $$\theta$$. Remember that you can express r in terms of $$R_{Circ}$$ and $$\theta$$.