What is a Force?

Max, Boots, and Bear are at the starting line. Today is the day of the Big Science Race. To move, they need to use a Force. A Force is just a push or a pull. Without a Force, the race can't even begin.

Are We Moving?

"Are we moving yet?" asks Bear. Max points to a bright flag stuck in the dirt. This flag is a Reference Point because it stays still. Since the friends are getting further from the flag, they are in motion! It's the best way to see how far they've gone.

Speed: How Fast?

Boots the Robot is super fast. Max checks his watch to see how quickly Boots zooms. This is called Speed, and Boots has a lot of it. Bear is much slower because he likes to take his time. Speed is just distance divided by time.

"Wait, Boots!" shouts Max. Boots is going fast,  but he is going the wrong way. His Velocity is wrong because he isn't heading toward the finish line. Velocity is speed plus a direction, like "10 miles per hour North." Boots, turns around to head the right way.

VELOCITY: WHERE TO?

The track has a giant, curvy bend. Everyone has to change their movement to stay on the road. This change is called Acceleration. You accelerate when you Speed up, slow down, or turn. The friends zoom around the curve with a big "Whoosh!"

Acceleration

Bear stops for a snack and won't move. Max says Bear has a lot of inertia. Inertia means objects like to keep doing what they are already doing. Since Bear is sitting, he wants to stay sitting. It takes a big force to get a "lazy" object moving.

Inertia

Max and Boots both grab Bear's paws. If they pull with the same strength, the forces are Balanced and nothing moves. But when Boots uses his rocket Boots, the force becomes Unbalanced. Now the Net Force pulls Bear forward. The team is finally back on  track.

Balanced Forces

The team has to push a heavy wagon full of apples. Bear tries to push, but it is very hard to move due to friction. This is because more Mass needs more force to accelerate. The wagon is heavy, so it needs a giant push. They all push together to get it rolling.

Friction