The planet Mercury travels around the Sun with a mean orbital radius of 5.8×1010 m. The mass of the Sun is 1.99×1030 kg. Use Newton’s version . . .

Question : The planet Mercury travels around the Sun with a mean orbital radius of 5.8×1010 m. The mass of the Sun is 1.99×1030 kg. Use Newton’s version of Kepler’s third law to determine how long it takes Mercury to orbit the Sun. Give your answer in Earth days.

Doubt by Nisha

Solution :

Orbital Radius of the Mercury around the Sun, r = 5.8×1010 m
Mass of Sum, M = 1.99×1030 kg

Using Kepler's Third Law of Motion
T2=kr3
T2=(4
π2/GM)r3
T2=
4π2r3/GM
T2= [4(3.14)2(5.8×1010)3]/[6.67×10-11×1.99×1030]
T2 = [39.4384×(5.8)3×1030+11-30]/6.67×1.99
T2 = [7694.905×1011]/13.2733
T= 579.728×1011
T = √(57.9728×1012)
T = 7.614×106 sec
T= 7.614×106/(60×60×24)
T = 88.125 days