Question

1. Under an apple tree Newton discovered that the reason the apples fall from the tree is the same reason the Moon orbits the Earth. Gravity! (a) Use Newton's law of gravitation to calculate the gravitational attraction betweenthe Earth and the Moon. Explain what measurement you will use. (b) How does the force of gravity change if the Moon got knocked 3 times further away? Would it increase, decrease or remain the same.

Answer 1

To find

(a) Newton's law of gravitation required to calculate the gravitational attraction between the moon and the earth and also the measurements required to calculate.

(b) Change in force of gravity if the moon is knocked 3 times away-(increase/decrease/remain same)

Step-by-step explanation:

According to Newton's law of gravitation, the gravitational force of attraction between the earth and the moon will be

`F=(GMm)/(r^2)`

Here, M is the mass of the earth

m is the mass of the moon

r is the distance between the moon and the earth

G is the universal gravitational constant whose value is

`G=\text{ 6.67}*10^(-11)\text{ Nm}^2\text{ /kg}^2`

Measurements required to calculate the gravitational force are the mass of the earth, the mass of the moon and the distance between them.

(b)

If the moon is knocked down 3 times further, the distance between the moon and the earth will increase.

As the gravitational force is inversely proportional to the distance between them, so the force will decrease.