Once upon a time, there was a little girl named Nikki who loved to play with balloons. She liked to blow them up, tie them with strings, and watch them float in the air. She also liked to play with rocks. She liked to collect them, paint them, and stack them on top of each other.
One day, Nikki had a bright idea. She wanted to see what would happen if she tied a balloon to a rock. She thought maybe the balloon would lift the rock up and make it fly. She ran to her room and grabbed a balloon and a rock. She blew up the balloon and tied it to the rock with a string.
She was very excited to see what would happen. She let go of the balloon and the rock and waited for them to fly. But nothing happened. The balloon and the rock just stayed on the ground. Nikki was confused and disappointed. She wondered why the balloon could not lift the rock.
She decided to ask her father for help. She took the balloon and the rock to her father and showed her what she did. She asked her father,” Papa, why the balloon could not lift the rock?”
Her father smiled and hugged her. He told her that it was a very good question and that she was very smart for trying to find out. He explained to her that it had something to do with something called mass and weight.
He told her that mass is how much stuff something has inside it. For example, the balloon has very little stuff inside it, mostly air, so it has very little mass. The rock has a lot of stuff inside it, mostly minerals, so it has a lot of mass.
He told her that weight is how heavy something is because of gravity. Gravity is a force that pulls everything down towards the earth. For example, the balloon is very light because gravity does not pull it down very much. The rock is very heavy because gravity pulls it down a lot.
He told her that when she tied the balloon to the rock, she made them into one thing. And that one thing had both the mass of the balloon and the mass of the rock. And it also had both the weight of the balloon and the weight of the rock.
He told her that because the rock had much more mass and weight than the balloon, it made the whole thing too heavy for the balloon to lift. The balloon could not overcome the gravity that pulled down on the rock.
He told her that if she wanted to make the rock fly, she would need a lot more balloons, or a much bigger balloon, or a much smaller rock.
Nikki understood what her father said. She thanked her father for explaining it to her. She decided to try again with different balloons and rocks. She had fun experimenting with different combinations and seeing what would happen.
She learned a lot about mass and weight that day. And she also learned that asking questions and trying new things is a great way to learn things.
Short stories for kids 