Fenna sends a pulse down a rope whose far end is tied to a brick wall. The pulse reaches the wall, then comes racing straight back along the rope.
The wall did not budge, and the pulse did not vanish. What happened at that boundary?
A wave travels until it meets the edge of its medium, or something blocking its way. Either one is a boundary.
When the wave cannot pass through the boundary, it does not stop there, and it does not disappear. It bounces back into the medium it came from.
The reflected wave travels back through the same medium, so it travels at the same speed as before.
Water waves reflect too. A ripple that reaches a pool's concrete edge bounces back and crosses the pool again.
Reflection needs a boundary the wave cannot pass through: a wall, a post, a pool's solid edge. The open middle of a pond turns nothing back.
A ripple spreads across a backyard pool and reaches the far concrete edge. What happens next?
The concrete edge is a boundary the ripple cannot pass through.
A wave meeting such a boundary bounces back into its medium.
The ripple reflects: it bounces back from the edge and travels back across the pool.
Griet flicks a pulse along a hallway rope tied to a door handle. The pulse reaches the handle. What happens, and at what speed does the pulse return?
The handle is a boundary the pulse cannot pass through, so the pulse reflects back along the rope.
The returning pulse travels through the same rope as before.
The pulse reflects and returns along the rope at the same speed it arrived with.
A ripple in a bathtub reaches the tub's end wall. What does the ripple do there?
Griet says: 'A wave that meets a boundary it cannot pass through bounces back into the medium it came from.' Is Griet correct?
A pulse on a rope reaches a post it cannot pass and bounces back. What is this bouncing back called?
A ripple crosses a fish pond and reaches a smooth rock ledge it cannot pass. What happens to the ripple?
Which statement describes reflection?
Four waves meet four obstacles. Which wave reflects?