A small object oscillates back and forth at the bottom of a frictionless hemispherical bowl, as the

Question:

A small object oscillates back and forth at the bottom of a frictionless hemispherical bowl, as the drawing illustrates. The radius of the bowl is R, and the angle u is small enough that the object oscillates in simple harmonic motion. Derive an expression for the angular frequency v of the motion. Express your answer in terms of R and g, the magnitude of the acceleration due to gravity.