* Gravity: This force always acts downwards, constantly pulling the projectile towards the Earth.

* Air resistance: This force, also known as drag, opposes the motion of the projectile. Its direction is opposite to the projectile's velocity.

Therefore, gravity acts downwards when a projectile is moving upwards.

It's important to note that while air resistance opposes the projectile's motion, it doesn't act solely downwards. Its direction is always opposite to the projectile's velocity.