A drone hovers over a pond just after a pebble drops in. From above, the ripples are rings: circle after circle sliding outward, every ring a line of crests seen from the top.
Side views carried this topic so far. The top view adds one new object, and later parts of this course lean on it.
From above, a single ripple ring marks water at the same stage of its oscillation all the way around: every point on the ring is at a crest at this instant.
Each ring in the drone's view is one wavefront: a line of crests seen from above.
Adjacent wavefronts sit one wavelength apart: from a line of crests to the next line of crests is the same crest-to-crest distance the side view showed.
A point source like the pebble makes circular wavefronts.
A long straight source, like a board rocked evenly in a wave tank, makes straight wavefronts, parallel to the board.
Read a wavefront diagram by its spacing: the gaps between adjacent fronts are the wave's wavelength, drawn to scale.
A map view shows circular ripple rings spreading around a bobbing float, with adjacent rings 0.4 m apart everywhere. What are the rings, and what is the ripples' wavelength?
Each ring joins neighboring points at the same stage of oscillation: each ring is a wavefront.
Adjacent wavefronts sit one wavelength apart.
The rings are wavefronts, and the wavelength is 0.4 m.
From a cliff, Dilys sees long straight swell lines approaching a beach, evenly spaced. What does each line mark?
Each line joins neighboring water at the same stage of oscillation: a line of crests seen from above.
A line of same-stage neighboring points is a wavefront.
Each swell line is a wavefront: one line of crests seen from above.
On a top-view diagram of ripples, what does the distance between two adjacent wavefronts equal?
A long straight paddle rocks steadily at one end of a wave tank. What shape are the wavefronts it sends out?
Anselm says: 'Seen from above, a line drawn along one ripple ridge joins points that are all at the same stage of their oscillation.' Is Anselm correct?
Which statement defines a wavefront?
A map shows circular wavefronts around a fountain jet, spaced 0.5 m apart everywhere. Which statement is correct?
A line of crests seen from above is called a ___.