- #1

AzimD

- 41

- 8

- Homework Statement
- A bead lies on a frictionless hoop of radius R that rotates around a vertical

diameter with constant angular speed ω, as shown in the figure below.

(a) What should ω be so that the bead maintains the same position on the hoop, at

an angle θ with respect to the vertical? Express you answer in terms of some or

all of the following: θ, R and g.

(b) Analyzing the answer for Part A, you will find that there is a range of angular

speeds, 0 < ω < ωo for which the fixed angle θ = 0 (meaning that the only

balanced position is at the bottom of the hoop). Find the value of ωo. Express

you answer in terms of some or all of the following: R and g.

- Relevant Equations
- a_r=-rω^2 (I'm not sure if it's relevant but I think it is.)

For whatever reason, I'm having a hard time conceptualizing this problem. I understand that the tangential components of all forces involved need to cancel out in order for the bead to be stationary. I also understand that there is a mgsinθ in the negative θ-hat direction. What I don't understand is to find the force opposite of it.