Question

the mass of moon is 1/81 of the mass the Earth .if gravitational force of the Earth on moon is f. then the gravitational force of moon on earth is.​

Answer 1

We have to use the formula

[math]F = \frac{G \cdot M \cdot m}{d^2}[/math] to calculate the force of attraction between Earth and Moon. I will be using the scientific notation in a way that 12E34 means 12 × 10^34.

These are the values we have to use:

Mass of Earth (mₑ) =

5.972E24 kg

Mass of Moon (mₘ) =

7.34767309E22 kg

Distance between Earth and Moon (d) = 384,400 km = 3.844E8 m

[math]F = \dfrac{6.674 \times 10^{-11} \cdot 5.972 \times 10^{24} \cdot 7.34767309 \times 10^{22}}{(3.84 \times 10^8)}[/math]

[math]F = \dfrac{6.674 \cdot 5.972 \cdot 7.34767309}{14.7456} \times \dfrac {10^{35}}{10^{16}}[/math]

[math]F = 19.86064 \times 10^{19}[/math]

[math]F = 1.986064 \times 10^{20}[/math] N is your answer

Answer 2

The mass of moon is 1/81 of the mass the Earth .if gravitational force of the Earth on moon is f. then the gravitational force of moon on earth is.​

F = G m1 m2/r²

G = constant

m1 = Mass of Earth

m2 = m1/81 = Mass of moon

r = Distance between then

Gravitational Force F between moon & Earth = F

if gravitational force of the Earth on moon is f

then the gravitational force of moon on earth = f also

Both will be same.