Final answer:
Once the cannonball is fired from the spaceship in space, no additional force is needed to keep it moving, due to the absence of friction or air resistance in space. This concept derives from Newton's first law of motion. However, external forces like gravitational pull from a nearby planet could impact the cannonball's trajectory.
Step-by-step explanation:
This pertains to the physical principle known as Newton's first law of motion, also referred to as the law of inertia. Once the cannonball is fired from the spaceship in space, it will continue to move in the same direction with a constant speed, unless acted upon by another force. This is due to the absence of friction or air resistance in space, which would eventually slow down the cannonball on Earth.
Thus, in the context of this , no additional force would need to be exerted on the cannonball to keep it moving once it has left the spaceship, as long as there are no other external forces in play (like gravitational pull from a nearby planetary body). The cannonball would move indefinitely until acted upon by an external force, according to Newton's first law of motion.
Rocket propulsion is a major example of this principle, wherein a rocket is propelled forward by expelling gas in the opposite direction with high velocity. The gas gets ejected after burning fuel, causing the rocket to move forward. Similarly, the cannonball will continue to move forward once fired. Therefore, understanding this principle provides insight into various astronomical concepts and space travel mechanics.
Learn more about Newton's first law of motion