Rotation of the radially slotted arm is governed by \(\theta=0.2 t+0.02 t^{3}\), where \(\theta\) is in radians and \(t\) is in seconds. Simultaneously, the power screw in the arm engages the slider \(B\) and controls its distance from \(O\) according to \(r=0.2+0.04 t^{2}\), where \(r\) is in meters and \(t\) is in seconds. Calculate the magnitudes of the velocity and acceleration of the slider for the instant when \(t=3 \mathrm{~s}\).