This is a simple science activity to do with your children. I love it when we only need to gather a couple of things to do a science experiment.
Find two balls with very different weights. We used a marble and a baseball.
Hold the balls in front of you so the bottoms of the balls are even.
Let go of the balls at the same time and observe which hits the ground first. Then try again from a higher point such as a balcony.
Which ball hits first?
Although at first it looked like the baseball was falling faster, but they both hit the floor at the same time. The acceleration due to gravity was the same for both balls even though they were different weights.