Question

Answer the following numercials :-
1) what is the time period of wave with the frequency of 250 Hz .
2) what is the frequency of the wave whose time period is 0.015 seconds .
3) Calculate the minimum distance required for an echo to be heard .
4) a boy fires the gun and here the echo two seconds later . if the boy is 350 m away from the velocity of the sound in air .
5) a girl claps and hear the Echo after reflection from a cliff which is 660 m away from the velocity of sound is 330 m/s , calculate the time for hearing the Echo


Correct answers will be mark as brainliest . ​

Answer 1

Answer:

1) 250= 1 / time period. time period =1 / 250. time period =0.004 seconds.

2) = 66.66 Hz.

3) So the minimum distance required to hear an echo in air is achieved by: d=343*0.05 or, d=17.15 Therefore to hear echo in air at room temperature, the minimum distance is 17.15m.

4) Complete Step by step solution

Given data, Distance between boy and object, d = 350 meter; Hence the total distance travelled for echo = 2d

Taken time by echo, t = 2 second

Velocity of sound, v =?

Hence, according the formula of distance;

Distance = Velocity x Time

⇒d=vt

⇒v=dt

⇒v=2dt

⇒v=2×3502

⇒v=350m/s

5) distance travelled by sound=2×660.

time=distance/speed.

=2×660/330

=4s