If i were to double the mass of a planet and kept the density the same will the gravity double

[hushed timber]

that one is better

the one you sent

G doesn't change in this situation

Im trying to picture this in head atm

i believe that the radius would not shrink

You need to maintain the density

youll need to maintain the ratio

because I double the mass, i need to double the volume to maintain the density is 2

[hushed timber]

fixed

I think those are 2 different questions

like the teacher is asking you write the surface gravity for case i and then seperatly case ii

if I'm thinking straight the radius is doubled

[stray delta]

If the density stays the same, how can an object shrink and also gain mass?

$M=\rho V$. If density is constant, then, $M\propto V$.

[deft nexus]

SWR

[stray delta]

radius is not doubled

volume is doubled

$V=\frac{4}{3}\pi r^3$. Thus, $V\propto r^3$

[deft nexus]

SWR

[stray delta]

If $V$ is doubled, then $r^3$ is doubled.

[deft nexus]

SWR

[stray delta]

Why is r squared? How are you getting that?

That's for gravitational acceleration, yes, but you haven't found the new radius yet.

Let $m_1$ be the mass of the first planet, $V_1$ its volume, and $r_1$ its radius. Let $m_2$ be the mass of the second planet, $V_2$ its volume, and $r_2$ its radius. The density of both planets is equal: $\rho$.

[deft nexus]

SWR

[hushed timber]

That gravity between two objects

[stray delta]

You are jumping ahead. We will use this, but you need the new mass and radius

2m1 m2 is not a mass.

Sorta, but I think you're saying it in confusing ways

You have a new planet with double the mass of your first planet, and the same density.

[stray delta]

Start here.

What is the mass of the first planet in terms of density and volume?

[hallow veldt]

a planet gives what is a gravitational field

which basically can help you calculate the force on IF there were another mass in the field

"gravity" of a planet is proportional to the force that would be exerted if there were a mass by the planet

you are seeing how it reacts for a given r

you have your planet

and lets say a basketball somewhere in space by the planet

and SWR is having you see the difference in the force exerted on the ball from the first planet

and if you replace your planet with the new planet

so I would go along with what SWR is saying

[hushed timber]

The person who was helping you