A mass attached to a spring is free to oscillate, with angular velocity ω, in a horizontal plane without friction or damping. It is pulled to a distance `x_0` and pushed towards the centre with a velocity `v_0` at time t = 0. Determine the amplitude of the resulting oscillations in terms of the parameters ω, `x_0` and `v_0`. [Hint : Start with the equation x = a cos (ωt+θ) and note that the initial velocity is