Question

the mass and the radius of the earth are N and n times , the mass and the radius of the moon respectively. the ratio of the average density of the moon to that of the earth, is then

Answer 1

Answer:

The weight of an object� depends on 'g' acceleration due to gravity, and the value of 'g' on earth: and moon is not same. The mass and radius of the earth is more than the mass and radius of the moon. As the weight of a body on the earth is 6 times more than the weight of a same body on moon.

Answer 2

Answer:

$n^3:N$

Explanation:

Let m be the mass of moon and r be the radius of moon.

Mass of earth=Nm

Radius of earth=nr

We have to find the ratio of the average density of the moon to that of earth.

Density=$\frac{mass}{volume}$

Volume of moon=$\frac{4}{3}\pi r^3$

Volume of earth=$\frac{4}{3} \pi (nr)^3=\frac{4}{3}\pi n^3r^3$

$\frac{Average\;density\;of\;moon}{Average\;denisty\;o\;earth}=\frac{\frac{m}{\frac{4}{3}\pi r^3}}{\frac{Nm}{\frac{4}{3}\pi n^3r^3}}=\frac{n^3}{N}$

$\frac{Average\;density\;of\;moon}{Average\;denisty\;o\;earth}=n^3:N$