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A Disturbing Situation
What happens when you sweep
your arm back and forth in a pool of
water? You make waves. Here’s how
it happens.
Your moving arm has energy. As you
sweep your arm through the water, this
energy of motion passes to the water.
The energy disturbs the water, making
it bob up and down. The energy,
however, doesn’t stay in one place.
It travels across the water’s surface,
disturbing the water all along the way.
Do you know what this disturbance is
called? That’s right—a wave!
Watch waves on a pond and you’ll
notice something important—the waves
don’t carry the water with them. The
water molecules move up and down as
the waves pass, but the molecules don’t
travel along with the waves.
What do waves on a pond have to do
with sound? Well, waves travel through
more than just water.
▲ A boat cutting across a bay generates
waves that move through the water.
The
Bottom
Line
Waves carry energy from one place to another.
Text reprinted with permission from SallyRideScience@UCSD for CA NGSS Rollout purposes only.
CA NGSS Rollout #3: Deepening Understanding of Scientific Modeling Elementary
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