Another Gravity Question (1 Viewer)

[cutemouse]

Hi, It seems like I'm on a roll here, but I think the answers may be wrong, so here's the question anyway:

"Calculate the gravitational force between the Moon and the Earth. The mass of the Moon is 7.35*10²²kg, that of the Earth is 5.974*10²⁴ kg. the diameter of the Moon is 3467km, that of the Earth is 12756km and the distance between them is about 406676km."

Thanks,

Jason

 

[lolokay]

the distance between the centres (R) is 12756 + the radius of the 2 bodies
the gravitational force is Gm1m2/R

 

[Aerath]

Isn't it R²? =\

 

[ratcher0071]

Hi, It seems like I'm on a roll here, but I think the answers may be wrong, so here's the question anyway:

"Calculate the gravitational force between the Moon and the Earth. The mass of the Moon is 7.35*10²²kg, that of the Earth is 5.974*10²⁴ kg. the diameter of the Moon is 3467km, that of the Earth is 12756km and the distance between them is about 406676km."

Thanks,

Jason

I think this might be correct. REMEMBER: d is the distance from the centre of the two masses.

F=Gm₁m₂ / d²
F=(6.67 x 10^-11) x (7.35 x 10²²) x (5.98 x 10²⁴) / ((0.5 x 3467x1000) + (0.5 x 12756x1000) + (406676 x 1000))²
F= 2.9316651 x 10³⁷ / 1.720486702 x 10¹⁷
F= 1.70 x 10²⁰ Newtons