A meteoroid is heading straight for Earth with a speed of 16.5 km/s relative to the center of Earth as it crosses our moon's orbit. What is its speed when it hits the surface of Earth? (Earth's mass: 5.97×10²⁴ kg, Earth's radius: 6.37×10⁶ m) a. 16.5 km/s
b. 15.2 km/s
c. 14.7 km/s
d. 12.8 km/s