Hmm , from your style of messages I think your real name is Yogesh(you were a member way back in the A5 forum) , ok anyway
Objects do accelerate, but to observe this you need a good drop height , 4 - 5 feet wont do, you should as said before try atleast 32 feet , which is impractical. I think the best solution you have is to increase the gravity vector, ok so it will not be quite like earths gravity but you will see the acceleration for shorter distances.