Answer: Newton's First Law of Motion, also known as the law of inertia, states that an object at rest tends to stay at rest, and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an external force. This law can be used to explain what happens when an asteroid collides with Earth as follows:
Asteroid in Space: Before the collision, the asteroid is in motion through space, following a specific trajectory and speed. According to Newton's First Law, it will continue moving in a straight line with the same speed and direction unless an external force acts on it.
Earth's Gravitational Force: As the asteroid approaches Earth, it comes under the influence of Earth's gravitational force. Gravity is the external force in this scenario, and it acts to accelerate the asteroid toward Earth's center.
Changing Trajectory: Due to Earth's gravitational attraction, the asteroid's path starts to deviate from its original straight-line trajectory. It begins to curve towards Earth as it gets closer.
Collision or Near Miss: Depending on various factors, such as the size and speed of the asteroid, it may either collide with Earth or experience a close approach. If it collides, it can cause significant damage, depending on its size and composition.
In summary, while the asteroid's motion through space is governed by Newton's First Law of Motion (inertia), its collision or near miss with Earth is primarily a result of the external gravitational force exerted by Earth. The gravitational force alters the asteroid's path, leading to the collision or near miss event.