The force of gravity between two bodies is proportional to the inverse square of the distance between the centers of the two bodies either exactly or approximately depending on nature of the bodies. At 10 Earth radii, the Earth's gravity force is times its gravity force on its surface. a) 1/10 b) 1/20 c) 20 d) 1/100 e) zero 34. The escape velocity for a small body from a large spherically symmetric body is v = 2GM r , where M is the mass of the large body, r is the radius from which the launch occurs (which could be on or anywhere above the body), and G = 6.67430 1011 is the gravitational constant in mks units. The launch can be any direction at all as long as only gravity acts on the small body: you cannot let the small body hit the planet. Calculate the escape velocity from the Earth given M = 5.9722 1024 kg and r = 6.3781370 106 m (which is the Earth's equatorial radius). Give the answer in km/s. a) 7.91 km/s. b) 0.791 km/s. c) 1.0 103 km/s. d) 11200 km/s. e) 11.2 km/s. 35. Kinetic energy is the energy of: a) motion. b) the electromagnetic field. c) electromagnetic radiation. d) rest mass. e) speediness. 36. The Einstein equation E = mc2 , where E is an amount of energy, m is mass, and c is the vacuum speed of light, can be read correctly in two ways. First, it can be read as saying all forms of energy have mass (i.e., resistance to acceleration and gravitational "charge") equal to E/c2, where E is the amount of the energy. Second, it can be read as saying: a)