1. The problem statement, all variables and given/known data Say there were 2 balls of different masses projected at the same angle and subjected to the same air resistance. Will the heavier ball reach a higher maximum vertical height than the smaller ball or vice versa? This is for my school experiment for projectile motion. I realised that the theoretical height I calculated was almost equal to the actual height it reached in real life. However, the theoretical horizontal displacement I calculated was MUCH more than the actual. Is this possible? 2. Relevant equations 3. The attempt at a solution I calculated the theoretical height to be 1.996 metres and the actual height turned out to be 1.2 metres which is even higher it was probably around the same. However, when I calculated the horizontal displacement, the theoretical was 2.7716 metres while the actual was 2.4 metres...is there a reason why this has happened? Why would the air resistance only take affect after the ball had reached it's maximum height?