Answer
given,
![y(x,t)=B cos[2\pi ((x)/(L) - (t)/(\tau))]](https://img.qammunity.org/2021/formulas/physics/college/e0q1pp8eu1ed5xyzkkuikzbrx2gbcuo9jp.png)
B = 6.40 mm , L = 26 cm , τ = 3.90 × 10⁻² s
general wave equation
y = A cos (k x - ωt)
where A is the amplitude of the
a) Amplitude of the given wave
B = 6.40 mm
b) Wavelength of the given wave
λ = L
λ = 26 cm
c) wave frequency
![f = (1)/(\tau)](https://img.qammunity.org/2021/formulas/physics/college/ddfu0iwybrag4vqb1qg55tbnrot8tkfabs.png)
![f = (1)/(3.9 * 10^(-2))](https://img.qammunity.org/2021/formulas/physics/college/wv1d9c70w9y5yx85bawsckcgs9q3xovahm.png)
f = 25.64 Hz
d) speed of wave will be equal to
v = f λ
v = 25.64 x 0.26
v = 6.67 m/s
e) direction of propagation will be along +ve x direction because sign of k x and ωt is same as general equation.