A man stands one-third of the way between two walls and claps his hands, He hears two distinct echoes 1s apart. If... - TEEZAB

A man stands one-third of the way between two walls and claps his hands, He hears two distinct echoes 1s apart. If…

JAMB 1980

A man stands one-third of the way between two walls and claps his hands, He hears two distinct echoes 1s apart. If the speed of sound is 330ms-1 the distance between the wall is

A. 33m

B. 110m

C. 220m

D. 330m

E. 495m

Correct Answer: Option E

Explanation

the man was standing at one third of d(distance between two walls), that means that he is 2/3 d from the other wall, and the echo were distinct echoes (not same reflection)

so since the v is same, make v subject for the two echoes

first echo distance=1/3d, time =x,

for second echo distance=2/3d, time =(x+1)seconds

from eqn v=2d/t

therefore (2(1/3d))/x =(2(2/3d))/x+1

after solving this u would get x =1

then sub 1 for x in the equation v=2d/t to get ur d, so 330=2(1/3d)/1, d =495

Or 

v=2d/t

but the man stands one third of his distance =⅓d

Therefore, v=2×⅓d/t

330=2×⅓d/1

330=2d/3

Making d the subject formula

2d=330×2

d=990/2

d=495

Explain your answer in the comment box below and let’s have a discussion so as to have a great understanding of this question!

PREVIOUS           NEXT

GO BACK TO THE PAST QUESTIONS PAGE

If you find this post beneficial, feel free to use the share button to share with friends.

Follow us on our Facebook page and subscribe to this website for more updates by hitting on the bell icon by the bottom left corner of your screen!

Leave a Comment

Your email address will not be published. Required fields are marked *