A cannon with a long barrel fires a shell faster because the shell experiences a greater ____________________.
A) change in inertia.
B) impulse.
C) acceleration.
D) None of these.
The correct answer is C) acceleration.
When a cannon fires a shell with a long barrel, the shell experiences a greater acceleration, which means it gains more speed in a shorter amount of time. This is because the longer barrel provides a longer distance for the expanding gases from the gunpowder to push against the shell. The force acting on the shell is directly related to its mass and acceleration according to Newton's second law (F = m*a).
To find the answer to this question, we can eliminate options A) and B) and focus on option C). Impulse refers to the change in momentum of an object, but it does not directly relate to the speed or acceleration of the object. Option D) suggests that none of the given options are correct, but since we have determined that option C) is correct, we can conclude that D) is incorrect.
Therefore, the shell fired from a cannon with a long barrel experiences a greater acceleration, causing it to travel faster.