AI Tutor
Imagine rolling a heavy bowling ball down a lane. When it crashes into the pins, the ball slows down and the pins go flying everywhere!
Where did the pins get the power to fly through the air if nobody touched them directly?

Moving Energy from Object to Object

In science, energy is the ability to cause change or make things move. When energy moves from one place or object to another, we call that an energy transfer.
The moving bowling ball had kinetic energy, which is simply the energy an object has because it is moving.
So how does kinetic energy actually jump across from one object to another?

Forces Are the Movers

Energy cannot just jump across empty space on its own — it needs a force, which is a push or a pull between objects.
When the rolling ball collides with a pin, its surface pushes against the pin. That push is the contact force that transfers kinetic energy from the ball to the pin.
In the 1840s, an English scientist named James Joule did careful experiments with falling weights and spinning paddles to prove that mechanical forces reliably transfer energy every single time.
What happens if one moving object hits a whole line of resting objects?