**1. What happens to air resistance in problems involving projectile motion?**

In the mathematical treatment of projectiles, at this level, air resistance is ignored.

**2. What effect does gravity have on projectile motion?**

The only force acting on the body is that of gravity. There is no horizontal accelaration acting on the body and therefore the horizontal velocity remains constant.

There is a constant acceleration for the vertical motion of

a = -gwhich is due to gravity.

**3. Is the variation in the force of gravity, due to altitude etc, taken into account?**

Any variation in the force of gravity is ignored in the mathematical treatment of this type of problem at this level.