Fourth Grade
Worksheets
Forces Around Us
Look around you, and chances are you'll see things moving. Cars move. People move. Elevators move up and down in tall buildings. Shopping carts move around in supermarkets. Balls fly through the air when they are thrown. You might not think about why these things move. Cars, elevators, and balls don't just move by themselves. Something is making them move. Forces make things move.
A force is a push or a pull. If you had a heavy box to move across your room, you might push it or pull it. The force would be working on the box in the same direction. It wouldn't matter to the box if you pushed it or pulled it. The amount of force needed to move the box would be the same. The direction of the force would also be the same.
When you push or pull a box, it is easy to see where the force is coming from. But it's harder to see forces at work when we think about a person or an animal moving. When you walk across the room, what force is making you move?
When you take a step, your foot is pushing down on the floor. That push is the force that makes your body move. When your foot pushes down on the floor, the floor pushes back. If the floor didn't push back, your foot wouldn't stop pushing down. You wouldn't go anywhere. You might end up standing in a hole.
Have you ever tried to walk in deep snow? It's much harder to walk in snow than it is on solid ground. The snow is too soft; it can't push back as hard as the ground does.
