How can one verify that the surface gravity on Mars is 40% that of Earth?
Because g = G m1 * m2/r * r = Newton’s law of universal gravitation g is the gravitational attraction between two bodies – in this case, you and Mars assuming that you were standing on the surface. G is the gravitational constant which is admittedly a magic number of a fudge factor. m1 is your mass. m2 is the mass of Mars. r is the distance between you and the centre of gravity of Mars. Plug in the numbers and you get around 40%. The real question is how you work out the mass of Mars. You do that by seeing how much it attracts/is attracted by other objects.
