A road runs between two parallel rows of buildings.A motorist moving just in the middle with a velocity of 30 km/h, sounds the horn. He hears an echo one second after sounding the horn. Find the distance (in metre) between thetwo rows of the buildings. The velocity of sound =330 m/s.

A road runs between two parallel rows of buildings.A motorist moving j

1.	A road runs between two parallel rows of buildings.A motorist moving just in the middle with a velocity of 30 km/h, sounds the horn. He hears an echo one second after sounding the horn. Find the distance (in metre) between thetwo rows of the buildings. The velocity of sound =330 m/s.
Answer» Solution :Suppose 2 y is the distance between two rows of the buildings. The distance travelled by a CAR in 1 SECOND `x=(30xx5/18)xx1=8.33m` The distance travelled by sound in 1 second `2l=330xx1=330m` `:.l=165m` From the figure `y=SQRT(l^(2)-(x/2)^(2))` `=sqrt(165^(@)-(8.33/2)^(2))` `=164.95m` Thus the distance between two rows of the buildings `2y=329.9m`

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A road runs between two parallel rows of buildings.A motorist moving just in the middle with a velocity of 30 km/h, sounds the horn. He hears an echo one second after sounding the horn. Find the distance (in metre) between thetwo rows of the buildings. The velocity of sound =330 m/s.

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