- Reflection of light
Ram is standing 165 m behind Shyam. Shyam is standing 'd' meters away from a wall in the same line. Ram claps and Shyam hears the clap two times at an interval of 2 seconds. Find the value of 'd'. (Assume velocity of sound to be 330 ms−1)
- 165 m
- 660 m
- 82.5 m
- 330 m
If ‘x’ is less than 60m and the time between the first and the second echo is 0.25s, then calculate the distance ‘x’.
Velocity of sound in air is 344 ms−1.
Why echoes can't be heard in a small room?
Because time gap between direct sound and reflected sound is too low to be perceptible by human ear
Because small rooms reflect less amount of energy
Because small rooms absorb more sound
Because of multiple reflections in small rooms
The speed of sound in air is 344 m/s. In order to hear distinct echoes in air, the distance of the obstacle from the source of sound should be:
at most 17.2 m
at least 17.2 m
equal to 17.2 m
depends on the medium
- 58 m
- 1032 m
- 68 m
- 1000 m
- 0.05 s
- less than 0.1 s
- less than 0.05 s
- more than 0.1 s
Statement 1: Ram is standing at a distance of 33 m from a wall. He claps and hears the echo of his own clap.
Statement 2: Velocity of sound in air is 330 m/s and time of persistence for hearing is 110 of a second.
Statement 1 is false but information in statement 2 is insufficient to prove it
Statement 1 is false and information in statement 2 is sufficient to prove it
Statement 1 is true and information in statement 2 is sufficient to prove it
Statement 1 is true but information in statement 2 is insufficient to prove it
A man standing in front of a vertical cliff fires a gun and hears the echo after 4 seconds. He moves 150 m towards the cliff and again fires the gun. This time, he hears the echo after 3.6 seconds. Find the distance of the cliff from his first position.
What is an echo?
Reflection of sound reaching to the listener some time before direct sound
Reflection of sound reaching to the listener some time after direct sound
Reflection of sound reaching to the listener with direct sound
Depends on position of listener