Once upon a time there was a girl named Goldi-drops who wanted to participate in a bike riding competition. One problem was she had trouble staying on her feet, for she was a very clumsy person. She was nicknamed Goldi-drops for this reason.

One day, she stumbled into a bike shop on an afternoon, and she saw a big, perfect bike for her. What luck! She needed a new bike because hers was worn out.

The first task of the competition was to ride up and down hills.

Goldi-drops tried to practice but her bike would not move! She pedaled with all her might but her new bike would not go. Maybe because my bike's wheels are too rough and too big. Maybe the friction, which opposes motion, between the ground and wheels is too much, she thought. Friction makes things harder to move!

Friction Wheels

All this pedaling made Goldi-drops very tired, so she traveled into a local restaurant to grab a drink. She noticed her ice was floated to the top of the drink because its' density is less than the drinks'. The mass of the ice was much less than the volume of the cubes. Buoyancy is the ability of an object to float in a fluid.

Gravity

Buoyancy

Goldi-drops went back to the bike shop, because her last one was too heavy to use and the weight was too much. Suddenly, she saw a small, perfect bike for her! The frame was light in weight, the volume was small, and the friction looked less because the wheels were smoother, all the things her last bike lacked.

The next part of the competition is to ride around in a circle. The bike is attached to a rope, and if you go too fast the rope will break, but the rope needs to be tight. I need to practice so I don't mess up!

Goldi-drops hopped on her bike and started pedaling slowly, and then she got faster until the rope was tight. She kept pedaling but there was not enough friction between her wheels and the ground, so she spun so fast she broke the rope!

Centripetal pull

Goldi-drops flew in a straight line right into a tree! She gained so much speed through centripetal force travelling in a circle, that when it was released, she traveled in a straight line. So far, the scientific forces have not been on her side.