Before PCs existed you had to physically test things for real. Nowadays you can simulate any experiment on the PC. And one such is this Projectile Motion, which simulates the behaviour of a cannon projectile on being shot out.
In Projectile Motion you just specify the angle, the start speed and the mass of the projectile. With this data you can shoot and check the distinct behaviours of that projectile depending on each of these factors. You can also add the level of air resistance.
For Projectile Motion to work correctly you need to have Java Virtual Machine installed.