Question

draw a curve showing density or pressure variation with respect to distance for disturbance produced by sound mark the position of compression and relation of this curve also define the wavelength and time period using this karo​

Answer 1

13. Initially, for convex mirror, u = − 60 cm, f = + 20 cm

Using mirror formula, 1 1 1

v u f

+ =

⇒

1 1 1

v f u

= − = −

−

1

20

1

( ) 60

=

+

=

3 1

60

4

60

⇒ v = 15 cm

∴ PB′ = 15 cm (1)

Let the plane mirror be held at M such that images in

the two mirrors coincide as shown below.

(1)

As, BM MB MP PB = ′ = + ′ = +x 15 …(i)

BM BB = ′ = + = 1

2

1

2

( ) 7.5 60 15 3 …(ii)

From Eqs. (i) and (ii), we get

x + = 15 37.5

⇒ x = − 3 15 7.5

= 22.5 cm

Answer 2

Answer:

Wavelength is the distance between two consecutive compressions or two consecutive rarefactions. Time period is the time taken to travel the distance between any two consecutive compressions or rarefactions from a fixed point.