Physics

posted by .

At a height of 15 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.150 s later. The air and water temperatures are 20°C. How deep is the lake?

  • Physics -

    look up speed of sound in water at 20C
    call it Cw
    look up speed of sound in air at 20C
    call it Ca
    then distance in water = 2d
    distance in air = 30
    time in water = t
    time in air = (.15 -t)
    then
    time in air = 30/Ca = .15 - t
    solve for t
    then
    Cw t = 2 d

  • Physics -

    Try some of the Physics Tutorials:

    http://search.yahoo.com/search?fr=mcafee&p=Physics+tutorial

    Sra

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    An airplane wants to drop a load of fish inot a small lake in the mountains. The plane is flying at its min speed 40 m/s, and is 50 meters above the surface of the lake. a.) Where relative to the lake should the plane be when the fish …
  2. math

    Surfact of A lake is 31 feet above the surface of B lake. B lake is half as deep as A Lake and the bottum of the B lake is 8 feet below the bottom of A Lake. how deep is each lake?
  3. physics

    A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. She hears the echo 1.7 s after shouting. Estimate the length of the lake.
  4. AP Physics

    At a height of 5 meters above the surface of a freshwater lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.140 s later. The air and water temperatures are 20°C. How deep is the …
  5. Physics

    The maximum depth of Lake Baikal, in Russia, is 1637 m, making it the world's deepest freshwater lake. If a beam of light with an angle of incidence of 60.0 degrees enters the water from the air, what is the horizontal distance between …
  6. physics

    a boy stands on a cliff overlooking a lake below. He throws a rock at an initial velocity of 8.0m/s,at an angle 25 degrees above the horizontal. The lake's surface is 4.5 m lower than the point the rock was released. Find the speed …
  7. PHYSICS - Waves

    Can someone tell me how to get the answer to this question?
  8. arithmetic

    a flower floats on the surface of lake water. its level above the lake surface is 5.5 cm. then a sudden gust of wind comes and flower sinks 10 cm far from its original point, what is the depth of lake at the point where the flower …
  9. Math

    Sadiq dropped his watch into a lake. The depth of the lake is 5 meters. Sadiq can dive down towards the bottom of the lake at a speed of 2 meters per second, but can swim upwards at a rate of 1 meter per second. How long will it take …
  10. physics

    A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. She hears the echo 2.20 s after shouting. How long (in meters) is the lake?

More Similar Questions