If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Different lights make me strange by changing me into different sizes. What am I?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

What Adam and Eve do not have but the rest of the people have?

The Little ant seems to be always confused. Do you know why?

Move four matchsticks to the below square to form three squares?

Move three sticks of the spiral below to form a square.

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?