Rocket wheels his bike out of the shed. His helmet dangles from the handlebars.
"Do I really need this for a short ride?" he asks.
Raven taps the soft foam inside the helmet. "Look at this layer. What do you notice about it?"
Nova scans the foam with a thin beam of light. "I found a pattern," she says. "This foam can crush. Why would engineers want that?"
Rocket thinks for a moment, then buckles the strap. "To take the bump instead of my head."
Bike helmets are designed to protect the brain and skull in a crash.
Inside is a layer of crushable foam. When a helmet hits something, the foam crushes and soaks up energy.
Health scientists found that wearing a bike helmet helps prevent head injuries.
A car crash is another collision. The car stops suddenly and releases its motion energy all at once.
Less speed means less energy to release. That is why slowing down near people matters.
Engineers ask: where will the energy go in a crash?
If the energy goes into a person's head, it can cause injury.
A helmet gives the energy a different place to go: into crushable foam.
Slowing down is another design choice. Less speed means less energy to begin with.
| Statement | True or false? |
|---|---|
| Bike helmets help prevent head injuries. | ? |
| A car crash is a collision. | ? |
| A faster crash releases less energy. | ? |
| Energy in a crash can be soaked up by foam. | ? |
Great job this week, crash scientist! Tomorrow is Launch Lab with a family bounce test.