Answer: 1.025*10^23 kg
Step-by-step explanation:
Given
Height of eruption, h = 5.1 km
Initial speed of the material, v = 132 m/s
Radius of moon, r = 2000 km
Mass of the moon, m = ?
We would solve this by using the formula
g = GM/r²
Also, we know that
h = v²/2g, substituting the formula of g into this equation, we have
h = v²/2(GM/r²)
h = v²r² / 2GM
Since we are looking for the mass, we make m the subject of formula, so that
M = v²r² / 2Gh
Now, substituting all the values, we get
M = [132² * (2000*10^3)²] / 2 * 6.67*10^-11 * 5.1*10^3
M = (17424 * 4*10^12) / 6.8*10^-7
M = 6.97*10^16 / 6.8*10^-7
M = 1.025*10^23 kg
Thus, the mass of the moon is 1.025*10^23 kg