2: A cannon fires an 8 kg cannonball into the air. At the highest point in its flight, before coming back down, the cannonball has a horizontal velocity of 35 m/s and is 15 m above the ground.
We can think about the mechanics of the cannon's firing as follows: while the ball was in the 1.5 m
long tube, it experienced an average force due to the explosion of gunpowder. The moment the ball
left the tube, it started to free fall (that is, fly in projectile motion) since this force is no longer
applied. What average force did the cannon's gunpowder explosion apply to the cannonball while it
was in the tube?