An astronaut weighs 696 N on the Earth. What is her weight on planet X, which has a radius Rx = Rearth 1.60 and a mass Mx = Mearth 8.60?

-the only equation I know for weight is "w = m x g"...I don't know how to solve for w using force.

Force on planet =

weight on planet =
G m Mplanet/Rplanet^2

Force on earth =
weight on earth =
G m Mearth/Rearth^2

so

weight on planet/weight on earth =

Mplanet/Rplanet^2
------------------
Mearth/Rearth^2

I think you can take it from there since Mplanet/ Mearth is given
and
Rplanet/Rearth is given

F=W=mg

F=G m ME\ RE^2
Rx =1.60
Mx =8.60

=ME\RE^2
=8.60\1.60^2
= Change the numbers from up to down and from down to up.
=1.60^2\8.60= 0.30
The astronaut weighs 696 N on the earth.
The weight on the planet X = 0.30*696=208.8 N

To find the weight of the astronaut on planet X, we can use the equation for gravitational force:

F = G * (m1 * m2) / r^2

Where:
F is the gravitational force
G is the gravitational constant, approximately 6.674 × 10^-11 Nm^2/kg^2
m1 and m2 are the masses of the objects interacting (in this case, the astronaut and planet X)
r is the distance between the center of the objects (in this case, the radius of planet X)

In this case, we need to find the gravitational force on the astronaut on planet X, so we can rewrite the equation as:

F = G * (m_astronaut * m_x) / r_x^2

Where:
F is the gravitational force on the astronaut
G is the gravitational constant
m_astronaut is the mass of the astronaut (which we'll assume to be the same on both Earth and planet X)
m_x is the mass of planet X
r_x is the radius of planet X

We are given the following values:
Weight of astronaut on Earth (F_earth) = 696 N
Radius of planet X (r_x) = 1.60 * R_earth
Mass of planet X (m_x) = 8.60 * M_earth

Since weight is the force acting on an object due to gravity, we can equate the weight on Earth (F_earth) to the gravitational force on the astronaut (F) on planet X:

F_earth = F

Now, using the equation for gravitational force, we can rewrite it as:

F_earth = G * (m_astronaut * m_x) / r_x^2

Substituting the given values:

696 N = (6.674 × 10^-11 Nm^2/kg^2) * (m_astronaut * 8.60 * M_earth) / (1.60 * R_earth)^2

Now, you can solve this equation for the weight of the astronaut on planet X (F):

F = (696 N * (1.60 * R_earth)^2) / (8.60 * M_earth) * (6.674 × 10^-11 Nm^2/kg^2)

Finally, plug in the values for R_earth and M_earth to calculate the weight of the astronaut on planet X.