Newton's second law of motion states that the force of gravity, F, in newtons, is equal to the mass, m, in kilograms, times the acceleration due to gravity, g, in metres per square second, or F, = mx g. On Earth's surface, acceleration due to gravity is 9.8 m/s downward. On the Moon, acceleration due to gravity is 1.63 m/s downward. a) Write a vector equation for the force of gravity on Earth. b) What is the force of gravity, in newtons, on Earth, on a 60-kg person? This is known as the weight of the person. c) Write a vector equation for the force of gravity on the Moon. d) What is the weight, on the Moon, of a 60-kg person?