Which One First?

8 Which One First? “ lf I drop an apple and a watermelon from the same height, which one will hit the ground first?" asks Tom. “ That's so easy! ” says Mary. The watermelon is big and heavy. It will hit the ground first. " Tom smiles. He knows what will happen. He says, “ No, they will hit the ground at the same time. " “ What? No way! ” Mary doesn't believe it. “ It's true. That's science, ” Tom says. Try it yourself!

I saw the two balls falling from here.