# Do question 3and 6 in a page

3. Given, λ = 100 m

v = 20 m/s

Since, v = f λ

f = v/λ = 20/100 = 0.2 hertz

6. The speed of the sound, distance traveled and the time taken relationship is given as follows.

Speed of sound=Time taken / Distance traveled

$Time=\frac{dis\mathrm{tan}ce}{velocity}\phantom{\rule{0ex}{0ex}}time=\frac{1650}{330}=5s\phantom{\rule{0ex}{0ex}}soBwillhearthesoundafter5seconds.$

Regards

**
**