Find gravitation on Mard and the Earth

[DollarBill]

Homework Statement

Mars Data:
Radius = .53 * Earth's Radius
Mass = .11 * Earth's Mass

Find the acceleration due to gravity on Mars in terms of g, the acceleration due to gravity on Earth.

Homework Equations

g=Gm / r²

The Attempt at a Solution

g_m= G(.11 M_E) / .53r_E²

g_E = Gm_E / r_E²
9.8 m/s²= Gm_E / r_E²

g_M/g_E

g_M=[G(.11 M_E) / r²] / [Gm_E / r_E²] * 9.8

g_M= .11/.53 * 9.8

g_M=2.034 m/s²

I'm not sure if this is right though.

 

[tiny-tim]

Hi DollarBill!

g_m= G(.11 M_E) / .53r_E².

Do you mean that, or have you written it wrong?

 

[DollarBill]

Hi DollarBill!


Do you mean that, or have you written it wrong?

Forgot the parenthesis...
g_M= G(.11 M_E) / (.53 r_E)².

 

[DollarBill]

Ok now I see what I did. Forgot to square the .53

g_M=3.8 m/s²