Question

A pendulum has a frequency of
5
vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after
8
vibrations of the pendulum. If the velocity of sound in air is
340

ms
−
1
, what is the distance between the cliff and the observer?

472

m
372

m
272

m
572

m
​

Answer 1

Answer:

Nobody knows for surе when spoken language first developed — it almost certainly wasn't invented. Written language has been around since about 3,300 BC, but spoken language does not appear in the historical or fossil record, so we do not know when it first developed.jj