You stand on a spherical asteroid of uniform density whose mass is 2 x 1016 kg and whose radius is 10 km. These are typical values for small asteroids. (a) How fast do you have to throw a rock straight up so that it never comes back to the asteroid and ends up traveling at a speed of 3 m/s when it is very far away? (d) Suppose you use a spring to launch a payload horizontally from the asteroid so that the payload ends up far from the asteroid, travelling at a speed of 3 m/s. The payload has a mass of 29 kg. If the spring is to be compressed initially an amount of 1.4 m, what stiffness ks must the spring be designed to have