

Explanation
(a) Sound wave travels faster on a hot day because the speed of sound is proportional to the square root of absolute temperature (V \(\alpha \sqrt{T}\)), hence the higher the greater the speed of sound wave.
(b) Megap:iones are shaped like a funnels because at the smaller end of the cone, the sound energy comes into contact will a small mass of air producing greater intensity. As it comes out of the larger open end, the energy sets a larger air mass into vibration, hence the final sound is louder.
(c) (i)

(ii) n = \(\frac{sini}{sinr}\)
sinr = \(\frac{sini}{n} = \frac{sin60}{1.5}\)
= \(\frac{0.8660}{1.5} = 0.5774\)
r = sin\(^{-1}\)0.5774 = 35\(^{o}\)
(d) a = \(\Omega^2r\) but \(\Omega = 2 \pi f\)
a = (2\(\pi f)^2\)r
f = \(\sqrt{\frac{9}{4 \pi^2 r}} = \sqrt{\frac{988}{4(\frac{22}{7})^2} \times \frac{1}{100}}\)
= 50Hz

