One string, or one air column, with a single mode drawn on it. Only the wavelengths that fit a whole number of half-waves between the ends survive, so L = nλ/2 and only a whole-number ladder of frequencies sounds.
Wavelength of this modelam = 2L / n
1.60000 m
Frequency of this modef_n = n v / (2L)
250.000 Hz
Fundamental frequencyf_1 = v / (2L)
250.000 Hz
Nodes and antinodes
2 nodes, 1 antinode
Length L0.800 m
Wave speed v400 m/s
Mode number n1
Boundary at the two ends
Published states7 presets
The mode conditionL = 1 x 1.60000 m / 2 = 0.800000 m
Node spacing (half a wavelength)0.800000 m
The first four modes250.000, 500.000, 750.000, 1000.00 Hz
VerdictFixed at both ends - a node at each end, so a whole number of half wavelengths fits
lam = 2L / n fixed or free, lam = 4L / (2n-1) one end fixed · f = v / lam, node spacing lam/2 in all three · n is a whole number: there is no half mode · the figures under the axis are node positions in metres · v is an input, what the medium sets, never derived here · the pattern's height and its rate on screen are drawing conveniences with no units, and no amplitude is printed.