Why is a truck so loud?
Video coming soon!
Play the games!
We found out!
The engine squeezes air until it's super hot
Hot air lights the fuel: BOOM! Lots of booms make the rumble
Big engine, big booms, big noise
The muffler makes it quieter
Meet the Truck Doctor!
The Truck Doctor fixes GIANT trucks. When a big truck gets sick, it comes to the shop to get better!
THE COOLEST SECRET
Coming with the video!
Try it at home!
Put your hand on your throat and hum. Feel the buzz? Sound is something shaking! A truck engine shakes a LOT.
For grown-ups
The big idea: sound is vibration. A diesel engine squeezes air until it's hot enough to ignite the fuel, and each ignition is a small, sharp burst. Many bursts every second make the rumble. The muffler quiets the exhaust.
How we know: the mechanic we visited checked every fact in this adventure.
Try at home: hum with a hand on your throat, then hum while touching a balloon or a paper cup. Talk about what's shaking.
Teachers: NGSS 1-PS4-1 (vibrating materials make sound).