What is the orbital period of mercury?

Question

i know the answer is 87.7 days, but how do you get this?

I tried the equation T=2(pie)r/v

The orbital radius(from the sun) is 57.9*10E9

or 57,900,000,000

Please help me!

Answer 1

its period is once every month

Answer 2

the orbital period for mercury or any other planet is governed by Kepler's third law,which states that :

(t/2*PI)^2=a^3/(G(M+m)),where t is the time period of revolution,G is the gravitational constant,M is the mass of the sun and m is the planet mass and a is the radius of revolution..this equation is valid only if you operate in the real situation in which reduced masses are involved.in case the question does not ask for reduced mass,we directly apply the equation,t=(2*PI*(a^1.5))/sqrt(G*M),wher... the terms stand for the same things as before.M=1.98892*10^30 kg.

G=6.67*10^-11N-m^2/kg^2,a=57.9*10E9,an... solve for the time in seconds and later convert into hours or days.note that in the second equation the mass of the orbiting planet is not involved.