Sir can you help me to solve this question on Physics
Two persons p and q are standing 100m away from a high wall and separated by distance d. P claps and q hears two sound (direct and echo) with a time difference of 0.2sec. Find the distance between p and q
I don't know. I want to know the answer
To solve this question, we can use the speed of sound and the time difference between the direct sound and the echo.
Let's consider the following information:
- Distance between persons P and Q: 100m
- Time difference between direct sound and echo: 0.2 seconds
The speed of sound at room temperature is approximately 343 meters per second.
Now, let's break down the situation:
1. When person P claps, the sound travels directly to person Q. Let's call this time t1.
2. The sound also travels towards the high wall and reflects back as an echo. This also takes some time. Let's call it t2.
Since we know the time difference between the direct sound and the echo is 0.2 seconds, we can say:
t1 - t2 = 0.2 seconds
Now, let's calculate the time each sound takes to travel:
The direct sound has to travel from person P to person Q, covering a distance of 100m. We can use the formula:
Time = Distance / Speed
So, t1 = 100m / 343m/s = 0.291 seconds (approximately)
The echo sound has to travel two times the distance between P and Q because it has to cover the distance from P to the wall and then back to Q. So,
t2 = 2d / 343m/s
Now, we can substitute the value of t2 in the earlier equation:
0.291 - (2d / 343) = 0.2
Simplifying the equation:
0.091 = (2d / 343)
Multiply both sides by 343:
31.213 = 2d
Divide both sides by 2:
d = 15.6065 meters (approximately)
Therefore, the distance between persons P and Q is approximately 15.6065 meters.