A sound signal is simultaneously sent in air and water from a boat on

1.	A sound signal is simultaneously sent in air and water from a boat on a river. The echo of sound striked by river bed is heard in 4s, while echo striked by aeroplane is heard in 8s. Find the distance between aeroplane and river bed [velocity of sound in air = 350m/s, velocity of sound in water =1500m/s.1) 4.4km2) 6.7km3)8.8km4)13.4km
Answer» Answer: *4.4km* Explanation: Time taken to hear echo is half the time taken to cover the DISTANCE. As for echo we have to TRAVEL twice the distance. Distance TRAVELLED in river, sriver=vrivertriver=1500×2=3000m Distance travelled in AIR, sair=vairtair=350×4=1400m stotal=sriver+sair =(3000+1400)m=4400m=4.4km

A sound signal is simultaneously sent in air and water from a boat on a river. The echo of sound striked by river bed is heard in 4s, while echo striked by aeroplane is heard in 8s. Find the distance between aeroplane and river bed [velocity of sound in air = 350m/s, velocity of sound in water =1500m/s.1) 4.4km2) 6.7km3)8.8km4)13.4km

Answer»

Answer:

Explanation:

Time taken to hear echo is half the time taken to cover the DISTANCE. As for echo we have to TRAVEL twice the distance.

Distance TRAVELLED in river, sriver=vrivertriver=1500×2=3000m

Distance travelled in AIR, sair=vairtair=350×4=1400m

stotal=sriver+sair

=(3000+1400)m=4400m=4.4km