def nWaveAmplitude(M, bulletDiam, bulletLen, xmiss, patm=101e3):
    """
    Calculate N-wave overpressure amplitude

    Parameters
    ----------
    M -- Mach number
    bulletDiam -- bullet diameter in m
    bulletLen -- bullet length in m
    xmiss -- miss distance in m
    patm -- atmosperic pressure in Pa

    Returns
    -------
    pmax -- N-wave overpressure amplitude in Pa
    """
    pmax = 0.53 * patm * bulletDiam * ((M ** 2 - 1) ** 0.125) / (
            (xmiss ** 0.75) * (bulletLen ** 0.25))
    return pmax