Question

The moon's mass is 7.34x10-kg and it is 3.8x10m away from earth. Calculate the gravitational force of attraction between earth and moon

Answer 1

Again I think you did not give the right constants. So I would use the correct constants for mass of moon and distance from earth to moon.

The formula for force of attraction between any two bodies in the universe
F  =  GMm / r^2.      (Newton's Universal law of Gravitation).

G = Universal gravitational constant, G = 6.67 * 10 ^ -11  Nm^2 / kg^2.
M = Mass of Earth. = 5.97 x 10^24 kg.
m = mass of moon = 7.34 x 10^22  kg.
r = distance apart, between centers = in this case it is the distance from Earth to the Moon
   = 3.8 x 10^8 m.

(Sorry I could not assume with the values you gave, they are wrong, and if we use them we would be insulting Physics).


So F = ((6.67 * 10 ^ -11)*(5.97 x 10^24)*(7.34 * 10^22)) / (3.8 x 10^8)^2.
  Punch it all up in your calculator.
 
I used a Casio 991 calculator, it should be one of the best in the world.Really lovely calculator, that has helped me a lot in computations like this. I am thankful for the Calculator.

F = 2.0240 * 10^ 20 N.
So that's our answer.
Hurray!!

Answer 2

Using the gravity equation: force of gravity = (G*mass of object 1*mass of object 2)/distance between the objects^2, we can plug in the masses of the objects (5.97x10^24kg for earth, and 7.34x10^22kg for the moon) and the distance between the objects (3.8x10^8metres) and (6.67x10^-11 gravitational constant) for G, we get (6.67x10^-11*5.97x10^24*7.34^22)/(3.8x10^8)^2 which equals =2.02x10^20 which is the force of gravity