(a) Calculate the magnitude of the gravitational force exerted by Venus on a 60 kg human standing on the surface of Venus. (The mass of Venus is 4.9multiply1024 kg and its radius is 6.1multiply106 m.) N (b) Calculate the magnitude of the gravitational force exerted by the human on Venus. N (c) For comparison, calculate the approximate magnitude of the gravitational force of this human on a similar human who is standing 3 meters away. N (d) What approximations or simplifying assumptions must you make in these calculations? (Note: Some of these choices are false because they are wrong physics!) Ignore the effects of the Sun, which alters the gravitational force that one object exerts on another. Treat Venus as though it were spherically symmetric. Treat the humans as though they were points or uniform-density spheres. Use the same gravitational constant in (a) and (b) despite its dependence on the size of the masses.