The formula to calculate the frequency is:
𝑓 =𝑣*𝜆
f=λ*v
where
𝑣 is the speed of sound and
𝜆 is the wavelength.
Given:
𝑣 = 343 m/s
𝜆 = 44 cm = 0.44 m
λ=44cm=0.44m
Plugging in the values:
𝑓 = 343 / 0.44 ≈ 779.55 Hz
The period of a wave is the reciprocal of the frequency:
𝑇 = 1/𝑓
T= 1/779.55Hz ≈ 0.00128s(or 1.28 ms)