Question 17 (6 points) The universal gravitational constant is one of the most important constants in physics. Discuss the discovery, importance and the measurement of the universal gravitational constant. State any famous physicists who were the first to theorize its existence and measure it experimentally. When discussing the measurement of G, limit the explanation only to the early measurement methods. Question 18 (2 points) Explain Albert Einstein's principle of equivalence of gravity using a thought experiment. Question 19 (2 points) State two differences between Einstein's and Newton's theories about gravity. Question 12 (2 points) In a science fiction movie, an astronaut on an extrasolar moon drops a communication device from a height of (7.400x10^-1) m and it takes (1.5x10^0) s for the device to fall to the ground. Determine the gravitational field strength at the surface of this moon. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: Answer x10 Add attachments to support your work units