A rock is moving through interstellar space towards a snow ball. Describe the motion of the rock until it hits the snow ball (in terms of Newton’s First Law). According to Newton’s 3rd Law, what will be the reaction to the force of the rock on the snow ball? How will these two forces compare?
According to Newton's First Law of Motion, also known as the law of inertia, an object will continue in its state of motion unless acted upon by an external force.
In this scenario, the rock is initially moving through interstellar space towards the snowball. Assuming no external forces are acting on the rock, it will continue to move in a straight line with a constant velocity due to its inertia until it comes into contact with the snowball.
Now, according to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. So when the rock hits the snowball, it exerts a force on it. As a result, the snowball will exert an equal and opposite force back on the rock.
These two forces, the force of the rock on the snowball and the force of the snowball on the rock, will be equal in magnitude but opposite in direction. This is because of the principle of action and reaction stated in Newton's Third Law.