The earth has a mass of 5.98 × 10^24 kg and the moon has a mass of 7.35 × 10^22 kg. The distance from the centre of the moon to the centre of the earth is 3.84 × 10^8 m. A rocket with a total mass of 1200 kg is 3.0 × 10^8 m from the centre of the earth and directly in between the earth and the moon. Find the net gravitational force on the rocket from the earth and moon.

F = 4.48N

Explanation:

In order to calculate the net gravitational force on the rocket, you take into account the formula for the gravitational force between two objects, which is given by:

        (1)

G: Cavendish's constant = 6.674*10^-11 m^3kg^-1s^-2

r: distance between the objects

You have a rocket at the middle of the distance between Earth and Moon, then, you have opposite forces on the rocket.

If you assume the origin of a system of coordinates at the rocket position, with the Moon to the left and the Earth to the right, you have:

      (2)

Me: mass of the Earth = 5.98*10^24 kg

Mm: mass of the Moon = 7.35*10^22 kg

m: mass of the rocket = 1200kg

r1: distance from the rocket to the Earth = 3.0*10^8m

r: distance between rocket and Moon = 3.84*10^8m - 3.0*10^8m = 8.4*10^7m

You replace the values of the parameters in the equation (2):

The net force exerted over the rocket is 4.48N

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.

c) up is the direction the magnetic force is acting on the charge.