Question

Given that the acceleration of gravity at the surface of mars is .38 of what it is on earth, and that mars radius is 3400 km,determine the mass of mars.

I Understand that i need to use g=GM/R^2, but im not sure of how to solve for m, what would i do to get g=GM/R^2 to get m=gR^2/G? And why would I have to use scientific notation?

Answer 1

We need to use scientific notation because we deal with the massive value of planet mass and the too long distances (radius of planet) which are difficult to carryout if we write them in general form, for example, in genral form we need to write the mass of earth as

Me= 5972000000000000000000000 kg

In scientific notion we can simply write it as, Me= 5.972*10^24 kg

Scientific notionbis easy, handy and accurate

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Gravity on mars= 0.38* gravity on earth

GM/R^2= 0.38*9.8

6.67*10^-11" M/(3400*10^3)^2= 0.38*9.8

M= 6.454*10^23 kg

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Comment in case still any doubt persists,, good luck