Physics

posted by .

(1) body is taken to depth of 32km below the surface of the earth.
Calculate the percentage decrease in the weight of the body at this depth
(The radius of the earth is 6400km)

(2)A wire of mass per unit length 5.0gm-1 is stretched between 2 points 30cm apart.
The tension in the wire is 70N.
Calculate the frequency of the sound emitted by the wire when it oscillates in the fundamental mode.

(3)The periodic time of the pendulum executing simple harmonic motion is 2s. After how much interval from t = 0, will it displacement behalf of it amplitude?

  • Physics -

    1) The weight of the person is proportional to the mass of the Earth at lower values of the radius. This will be less by a factor of (6368/6400)^3 at the 32 km depth.

    2). Use the wide lineal density and the tension to compute the transverse wave speed, V.

    V = sqrt [Tension/(mass per length)]

    The length of the wire is half the wavelength of the fundamental mode. Call that wavelength W.
    W * f = the wave speed, V. Solve for f

    3) displacement = (Amplitude) sin (2 pi t/P)
    where P is the period. If displacement= amplitude/2, then
    1/2 = sin (2 pi t/P)
    2 pi t/P = pi/6 (30 degrees)
    t/P = 1/12
    t = 1/6 second

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    Assuming that 68.1% of the Earth's surface is covered with water at average depth of 1.21 mi. ,estimate the mass of the water on Earth. One mile is 1.609 km and the radius of the earth is 6.37 x 10^6 m. Answer in units of kg
  2. physics

    the mass of a body is 50 kg on the surface of the earth.find its weight on the surface of a planet whose mass is double than the mass of the earth and radius is 5 times the radius of the earth
  3. earth

    Body on surface of earth weighs 400 lb. Radius of earth is about 4000miles. If same body were placed on 4000 mile high tower, what would its weight be
  4. Physics

    a. 2 objects each of mass 200 kg and 500 kg are separated by 50 cm. Where body of mass 20 kg should be placed so that the resultant force of gravity experienced by objects equal to zero?
  5. physics

    If the change in the value of 'g ' at a height 'h ' above the surface of earth is the same as at a depth 'x ' below it. When both x and h are much smaller than the radius of the earth. The relation between x and h is?
  6. Physics

    A mass of 5Kg is 1st weighed on a balance at the top of a tower 20m high.The man is then suspended from a fine wire 20m long and reweivhed.find the difference in a weight ,assuming that the radius of the earth is 6400km,the mass of …
  7. maths

    The Weight of an object varies inversely as the square of its distance from the centre of the earth.the weight of a spacecraft is observed to be only a quater of its weight on earth.How far is the spacecraft from the surface of the …
  8. Physics

    the weight of the body on the surface of earth is 392N what will be the weight of this body in another body whose mass is double of earth mass and radius is fourth multiple of earth radius?
  9. Science

    The weight of a body on the surface of the earth is 392N .What will be the weight of this body on a planet whose mass is double that of the earth and radius is four times that of the earth
  10. physics

    with what velocity must a body be thrown from earth surface so that it may reach a height 4Re the earth surface. given Re=6400km g=9.8m/s

More Similar Questions