Question

The only force which acts upon a projectile is

Answer 1

Projectile:

1. A projectile is an item on which gravity is the sole force operating. There are several types of projectiles. A projectile is an item that is launched from rest. A projectile is an item that is hurled vertically upward.
2. A projectile is indeed an item that is hurled upward at an inclination to the horizontal.
3. This would be any item that, being projected or launched, keeps going due to its own inertia and is solely impacted by gravity's downward pull.
4. The force of gravity is the only force that operates on a projectile. If there was another force operating on an item, this would not be a projectile.

Therefore, the only force which acts upon a projectile is the force of gravitational force/gravity.