Question

A source produces 20 crests and 20 troughs in 4 seconds. The second crest is 3 cm away from the first crest.Calculate :

Answer 1

Answer:

Solution given:

No of waves[N] =20crests & 20 troughs

=20waves

Time[T]=4seconds

distance[d]=3cm=0.03m

Now

Wave length=3cm=3 × ${10}^{ - 2}m$

Frequency=$\frac{No of waves}{time}$

=$\frac{20}{4}$=5Hertz

and

Wave speed:wave length×frequency=3 × ${10}^{ - 2}m$×5=1.5 × ${10}^{ - 1} \tt{ {ms}^{ - 1}}$.