cannon!

yeah!! we'll be building our cannons on Thusday!! the cannon is made of 5 pop cans. according to last unit(projectile motion), we know that the best angle to set our cannons is 45°、because it would reach the farthest distance.
But of course, the real cannon is not made of pop cans..
A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellants to launch a projectile.