Into the Horizon

A planet (Blanc) is in a stable orbit with a radius of $7.5 \times 10^{12}\ m$ around a black hole (Noir). Blanc has a mass of $3.75 \times 10^{26}\ kg$ and a radius of $25000\ km$ . Noir has a mass of $2.5 \times 10^{31}\ kg$ . If intergalactic daredevil Zaphod Beeblebrox is fired in a spacecraft on a ballistic trajectory from the surface of Blanc directly towards Noir with an initial velocity of 2,500 km/s, how long until Zaphod reaches Noir? Assume no perturbations from other bodies and give your answer rounded to the nearest hour.