Suppose that a large, very dense asteroid with mass one hundredth (1/100) of that of the earth collides with our planet. assume that the asteroid hits the equator with a speed of 1000 km/s, that it comes in on a purely radial path, and that it stays near the surface of the earth after the collision. how long is an earth-day after the collision? (you can assume that earth has mass m = 6 × 1024 kg and radius r = 6400 km and has the shape of a perfect sphere).