State what is meant by a longitudinal travelling wave.

Calculate, for this wave,

(i) the speed.

(ii) the frequency.

The equilibrium position of a particle in the medium is at x=0.80 m. For this particle at t=0, state and explain

(i) the direction of motion.

(ii) whether the particle is at the centre of a compression or a rarefaction.

(i)
ALTERNATIVE 1
«distance travelled by wave =» 0.30 m

\(v = \ll \frac{{{\rm{distance}}}}{{{\rm{time}}}} = \gg 340{\rm{m}}{{\rm{s}}^{ - 1}}\)

ALTERNATIVE 2
evaluates \(T = \frac{{{\rm{0.882}} \times {{10}^{ - 3}} \times 1.6}}{{{\rm{0.3}}}}\)«=4.7ms» to give f = 210 or 212 Hz

uses λ=1.6 m with v=fλ to give 340ms^–1

(ii)
ALTERNATIVE 1
λ=1.60m

f=\(\frac{{340}}{{1.60}}\)=212 or 213Hz

ALTERNATIVE 2
\(T = \frac{{0.882 \times {{10}^{ - 3}} \times 1.6}}{{0.3}}\)«=4.7ms»

\(F =  \ll \frac{1}{T} =  \gg {\rm{ 210Hz}}\)

(i)
the displacement of the particle decreases OR «on the graph» displacement is going in a negative direction OR on the graph the particle goes down