When a cannon with a longer barrel is fired, the force of expanding gases acts on the cannonball for a longer distance. What effect does this have on the velocity of the emerging cannonball? (Do you see why long-range cannons have such long barrels?)
When a cannon with a longer barrel is fired, the force of the expanding gases continues to act on the cannonball for a longer distance. This has a significant effect on the velocity of the emerging cannonball.
To understand why, let's consider the principles behind how cannons work. When a cannon is fired, gunpowder or another explosive propellant is ignited inside the barrel. This explosion rapidly produces a large volume of gases, creating a high-pressure environment within the barrel. As a result of this pressure, the cannonball is propelled forward with a tremendous amount of force.
The force that propels the cannonball forward is the result of the expanding gases exerting pressure on the base of the projectile. According to Newton's third law of motion, this force creates an equal and opposite reaction force that propels the cannonball forward.
Now, let's examine the impact of a longer barrel on the cannonball's velocity. The longer the barrel, the longer the duration over which the expanding gases act on the cannonball. This means that the cannonball is subjected to the force for a longer period of time, allowing it to accelerate for a longer distance.
As a result, the cannonball can achieve a higher velocity when it emerges from a longer barrel. The longer distance over which the force is applied allows the cannonball to accelerate more effectively and reach a higher speed.
This is why long-range cannons have such long barrels. By giving the expanding gases more time to act on the cannonball, the cannon can achieve greater velocity and therefore greater range. A longer barrel allows for improved acceleration and more efficient transfer of energy from the propellant gases to the cannonball, ultimately resulting in a longer firing range.