What Is a Collision

A collision is what happens when two objects hit each other. Collisions happen all around us every day. When you accidentally bump into a friend in the hallway, that is a collision. When a soccer ball hits the goalpost, that is a collision too.

Understanding collisions helps us explain how objects move and what happens when they touch. In every collision, both objects are affected. If you roll a toy car into another toy car, both cars feel the hit. One car might stop moving while the other starts rolling. Sometimes both cars bounce backward.

The force in a collision is the push or pull that one object puts on another object. When a basketball hits the ground, the ball pushes down on the ground. At the same time, the ground pushes back up on the ball. This is why the ball bounces. Both the ball and the ground are part of the collision.

Collisions can be gentle or strong. When you catch a ball, that is a gentle collision between your hands and the ball. When a bowling ball knocks down pins, that is a stronger collision. In all collisions, energy moves from one object to another. Energy is what makes things move or change. During a collision, energy can make objects speed up, slow down, change direction, or even make sounds.

Scientists study collisions to understand motion and energy better. This knowledge helps engineers design safer cars and better sports equipment.