A 1 kg mass weighs 9.8 N on earth's surface, and the radius of the earth is roughly?

Question

Can you help me with these 2 problems. thnx.

1. A 1 kg mass weighs 9.8 N on earth's surface, and the radius of the earth is roughly 6.4 x 10^6 m. Calculate the mass of the earth.

2. Calculate the mass of the sun using Newton's version of Kepler's 3rd Law.

Answer 1

For the first problem :

Just use this :

g = GM / R^2 >>> gravity.

So :

m*g = GMm / R^2

m = mass of anything

M = mass of Earth

9.8 = GM*1 / R^2

G = constant = 6.67*10^-11

R = 6.4*10^6

9.8 = 6.67*10^-11*M / 6.64*10^6

9.75*10^17 kg = Mass of the Earth

Answer 2

F = G * m1m2/r^2 G = 6.67x10^-11 N·m2/kg2 m1 = a million.2kg m2 = fixing for r= 6.4*106m F = 11.seventy six remedy for m2 upon getting the mass, divide with assistance from the quantity of the earth, it extremely is about 4/3 pi*r^3 and remedy

Answer 3

the other guy forgot to suare the radius.

9.8 = (6.67*10^-11)*M / (6.64*10^6)^2

9.8 = 1.5*10^-24*M

9.8 / (1.5*10^-24) = M

Mass of Earth = 6.53*10^24