Observation

This was a popular question among candidates. Few candidates were able to define projectile motion but could but differentiate between projectile motion and motion under mechanical force.

The expected response is as stated below:

(a) Projectile motion
Movement of a body/particle thrown/released into air and acted upon by gravity only.

OR

Movement of a body thrown/launched upward/forward and allowed to fall only under its own weight/gravity.

(b) Explanation of why a flying plane is not considered a projectile
A flying plane moves under a force supplied by the engine.  Since the motion is not under gravity only, it is not a projectile.