JAMB - Physics (2018 - No. 59)
A man hears his echo from a nearby hill 2s after he shouted. If the frequency of his voice is 260Hz and the wavelength is 1.29m, how far away is the hill?
330.0m
335.4m
660.0m
670.8m
解释
Recall V = F × \(\lambda\)
= 260 × 1.29
= 335.4ms\(^{-1}\)
Echo time = \(\frac{2}{2}\) = 1 sec
Distance = v x t = 335.4 x 1
= 335.4m