Why does the moon not require a push to keep it along its orbit around the earth? -I have to use Newton's first law of motion.
To understand why the moon does not require a push to keep it along its orbit around the Earth, we can use Newton's first law of motion, also known as the law of inertia.
Newton's first law states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force. This law implies that if there are no external forces acting on an object, it will continue to move in a straight line at a constant speed.
In the case of the moon's orbit around the Earth, we can imagine that the moon is continuously moving in a straight line, but the gravitational force between the Earth and the moon causes the moon's path to curve into an orbit. This gravitational force is the external force acting on the moon and acts as a centripetal force, pulling the moon towards the Earth.
According to Newton's second law of motion, an object experiences a centripetal force when it moves in a circle. In the case of the moon, this centripetal force is provided by the gravitational attraction between the Earth and the moon.
The gravitational force between two objects depends on their masses and the distance between them. The Earth's mass is significantly greater than the moon's, and the distance between them remains relatively constant, so the gravitational force remains nearly constant.
Since the gravitational force acting on the moon always points towards the Earth, it continuously changes the moon's direction, keeping it in a circular orbit. The moon's inertia allows it to keep moving along its orbit, without requiring any additional push or external force to maintain its motion.
Therefore, according to Newton's first law of motion, the moon does not require a push to keep it along its orbit around the Earth because the gravitational force between the Earth and the moon acts as the required centripetal force to maintain the circular orbit.