Universal Law of Gravitation.
Classical Mechanics
Level
1
If a person weighs 70 kgs on the earth how much would he weigh on Mars. Calculate this ratio round it off to two decimal places. It is given that Mass of the Earth = 5.972 × 10^24 kg Mass of Mars = 6.39 × 10^23 kg Radius of Earth = 6,371 km Radius of Mars = 3,390 km
70 kgs.
11.67 kgs
185.5 kgs
26.42 kgs
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
By the universal law of gravitation the force acting on a mass m on the surface of an object weighing M is given by mg = GMm/R*R. So g (earth)/g (mars) is given by (Mass of Earth/Mass of Mars) * (Radius of Mars/Radius of Earth) * (Radius of Mars/Radius of Earth). Substituting the constants given in the problem g (earth)/g (mars) = 2.65 so a person who weighs 70 kg on the Earth will weigh 26.42 kgs on Mars (approx).