In an experiment to determine speed of sound in air, a drum at a point

150m from a vertical wall was struck

at varying frequency while listening

to the echo. The echo coincides with

the sound from the drum at a time

when to successive strikes were

made within a time of 18.5s.

i. Determine the time taken for

an echo to be heard

ii. Determine the speed of sound

in air at the place

iii. What difference would you

expect if the experiment was

repeated on a colder day?​