- #1

PsychonautQQ

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## Homework Statement

Two asteroids are traveling side by side, touching each other. They are both spherical and are made of pure iron. What must their diameters be in feet to exert a force of 3 lb's onto eachother?

## Homework Equations

V = 4/3*∏*r^3

density of Iron = 7.63*10^3

1 lb = 4.448N

1 foot = .3048 meters

F=Gm1m2/r^2

Vp = Mass

## The Attempt at a Solution

So subtitling Vp in for m1 and m2 and then combing the terms since they are equal...

(G(p*4/3*∏*r^3)^2) / 9r^2 = F

(p*G*16*∏^2*r^6 ) / 9r^2 = F

(p*G*16*∏^2*r^4 )/ 9 = F

((F*9) / (p^2*G*16*∏^2)) ^ (1/4) = r

3 lbs = 13.344N

1 ft = .3048m

So I solved this in terms of newtons and meters then converted the radius to feet and got 12.0 Feet and my online thing is saying it's wrong.... this r would be the distance between the COM's so it would equal the diameter of one of them

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