I believe this is what you have to do:
The force between a mass M and a point mass m is represented by

So lets compare it to the original force before it doubles, it would just be the exact formula so lets call that F₁
So F₁ = G(Mm/r^2)
Now the distance has doubled so lets account for this in F₂:
F₂ = G(Mm/(2r)^2)
Now square the 2 that gives you four and we can pull that out in front to give
F₂ =
G(Mm/r^2)
Now we can replace G(Mm/r^2) with F₁ as that is the value of the force before alterations
now we see that:
F₂ =
F₁
So the second force will be 0.25 (1/4) x 1600 or 400 N.
Answer:
R = m⁴/kg . s
Explanation:
In this case, the best way to solve this is working with the units in the expression.
The units of velocity (V) are m/s
The units of density (d) are kg/m³
And R is a constant
If the expression is:
V = R * d
Replacing the units and solving for R we have
m/s = kg/m³ * R
m * m³ / s = kg * R
R = m * m³ / kg . s
<h2>
R = m⁴ / kg . s</h2>
This should be the units of R
Hope this helps