Maria is jumping on a trampoline. The trampoline is at rest when no one is on it and the height is considered level at Ocm when resting. Each time that Maria jumps on the trampoline, the material depresses to a minimum height of $5$cm below resting point. On average she is reaching a maximum height of $255$cm above the revery $10$ seconds. Determine the equation of a sinusoidal function that would model this situation, assuming Maria reaches her first maximum at $4$ seconds.