I recently went to a math competition where i was entered into a physics competition, even though i hadn't had one minute of physics, but oh well. Anyway, i just wanted to know if one of the question we got could be considerd "hard".

Number 1. The Earth orbits the sun. The radius of its orbit around the sun is approximatly 1.5m x 10 to the 15 power. The time it takes to orbit aroun the sun is 27 seconds x 10 to the 20 power. What is the mass of the sun?


I'll post the other questions later, i have to go to school now.

"Hard", is a relative term. But in mathematical terms, this is not a hard question as long as you know the equation for finding the period of an orbit and the value of the gravitational constant. Then its just simple algerbra to solve for the unknown.

The equation BTW is

P = 2*pi * sqrt(r^3/(GM))

where P is the period
r is the radius of the orbit
G is the universal gravitational constant
M is the mass of the boby being orbited. (in this case the Sun)