1. A person is standing between two vertical mountains. the person fire a gun then hears the first echo from the nearby mountain in a time 3 second and here second echo from far mountain in a time 4 second. What is the distance between two mountains?
2. A boy is standing between two walls. the wall closer to him is at the distance of 680 m. if he shouts , he hears the first echo after 4 second and another after 2 second. What is the velocity of sound in air and what is the distance between two walls.
Answers
1. A person is standing between two vertical mountains. the person fire a gun then hears the first echo from the nearby mountain in a time 3 second and here second echo from far mountain in a time 4 second. What is the distance between two mountains?
Answer -
Mountain1 ----> Person-------> Mountain2
⠀[near]⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀[far]
Case 1
the distance from near mountain = x
Total time taken to hear an echo sound = 3sec
Speed of sound = 340m/s
Distance = Speed × time
2x = 340 × 3
x = 170 × 3 = 510 m
Case 2
the distance from near mountain = y
Total time taken to hear an echo sound = 4sec
Speed of sound = 340m/s
Distance = Speed × time
2y = 340 × 4
x = 170 × 4 = 680 m
★ Distance Between The Mountainous
= x + y
= 510 + 680
= 1190 m
_______________________
2. A boy is standing between two walls. the wall closer to him is at the distance of 680 m. if he shouts , he hears the first echo after 4 second and another after 2 second. What is the velocity of sound in air and what is the distance between two walls.
Answer -
wall--m---> Person--------x---------> wall
⠀[4sec]⠀⠀⠀⠀⠀⠀⠀⠀[6sec]
Case 1
Near Mountain :-
Distance = Speed × time
2×680 = Speed × 4
Speed = 2×680 ÷ 4
speed = 340 m/s
Case 2
far Mountain :-
Distance = x
Speed ÷ velocity of sound in air = 340m/s
time = 6sec
Distance = Speed × time
2x = 340 × 6
x = 340 × 6 ÷ 2
x = 340 × 3
x = 1020
★ what is the distance between two walls = 1020 + 680 = 1700 m
Answer:
1. A person is standing between two vertical mountains. the person fire a gun then hears the first echo from the nearby mountain in a time 3 second and here second echo from far mountain in a time 4 second. What is the distance between two mountains?
2. A boy is standing between two walls. the wall closer to him is at the distance of 680 m. if he shouts , he hears the first echo after 4 second and another after 2 second. What is the velocity of sound in air and what is the distance between two walls.1. A person is standing between two vertical mountains. the person fire a gun then hears the first echo from the nearby mountain in a time 3 second and here second echo from far mountain in a time 4 second. What is the distance between two mountains?
2. A boy is standing between two walls. the wall closer to him is at the distance of 680 m. if he shouts , he hears the first echo after 4 second and another after 2 second. What is the velocity of sound in air and what is the distance between two walls.