The mean orbital radius of the earth around the sun 1.5 × 108 km. Calculate the mass of the sun if G = 6.67 × 10-11 Nm2/kg -2?​

M = 1.994 × 10^(30) kg

Explanation:

We are given;

Orbital radius; r = 1.5 × 10^(8) km = 1.5 × 10^(11) m

Gravitational constant; G = 6.67 × 10^(-11) N.m²/kg²

If the orbit is circular, the it means the gravitational force is equal to the centripetal force.

Thus; F_g = F_c

GMm/r² = mv²/r

Simplifying gives;

GM/r = v²

M = v²r/G

Now, v is the speed of the earth around the sun and from online sources it has a value of around 29.78 km/s = 29780 m/s

Thus;

M = (29780^(2) × 1.5 × 10^(11))/6.67 × 10^(-11)

M = 1.994 × 10^(30) kg

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.