Question

12 multiple choice 3 points which of the following statements describes a result of earths gravitational pull on the moon? the moon has craters. the moon orbits around earth. the moon lacks an atmosphere. the moon has less gravity than earth. 13 multiple choice 2 points why does the moon only have \\( \frac { 1 } { 6 } \\) of the earths gravity? it is very far away from earth. it has less mass than earth. it is made of basalt. it has no atmosphere. 14 essay 4 points imagine you are on the space station and you release two objects of different masses at the same distance from the center of the earth. discuss whether the gravitational force exerted by the earth on each object is the same or different and then explain why.

Explanation:

12.

• The Moon having craters is due to impacts from asteroids, comets etc., not Earth's gravitational pull.
• The Moon lacking an atmosphere is related to its mass and escape velocity, not Earth's gravitational pull on it.
• The Moon having less gravity than Earth is about its own mass, not Earth's pull on it.
• According to Newton's law of gravitation, the gravitational force between two objects (here Earth and Moon) causes the Moon to orbit Earth.

• Gravity of a celestial body is given by \(g=\frac{GM}{R^{2}}\) (where \(G\) is the gravitational constant, \(M\) is mass and \(R\) is radius). The Moon's gravity is less because its mass (\(M\)) is much less than Earth's. Distance from Earth (for the Moon's own gravity) is not relevant as gravity of a body is about its own properties. Being made of basalt or having no atmosphere does not determine its gravity.

The gravitational force \(F\) exerted by the Earth on an object is given by Newton's law of gravitation \(F = G\frac{M_{E}m}{r^{2}}\), where \(M_{E}\) is the mass of the Earth, \(m\) is the mass of the object, \(r\) is the distance from the center of the Earth to the object, and \(G\) is the gravitational constant. Since \(M_{E}\), \(G\) and \(r\) are the same for both objects (released at the same distance from the Earth's center), but \(m\) (mass of the objects) is different.

Answer:

The Moon orbits around Earth.

13.