What's the linear mass density of a string?

A long uniform string of mass density 0.1 kg/m is stretched with a force of 50 N.?

• A long uniform string of mass density 0.1 kg/m is stretched with a force of 50 N. One end of the string (x=0) is oscillated transversely (sinusoidally) with an amplitude of 0.02 m and a period of 0.1 sec, so that traveling waves in the +x direction are set up. a) What is the velocity of the waves? b) What is their wavelength? c) If at the driving end (x=0) the displacement (y) at t=0 is 0.01m with dy/dt negative, what is the equation of the traveling waves? PLEASE HELP! DESPERATE! Thanks

• Answer:

  To find the velocity of waves in this string, look in your textbook for the formula that says "velocity of waves in a string". There you will find a formula in terms of mass per unit length (which you've been given) and tension force (which you've been given). Plug them into the formula and you'll get the velocity. The relationship between velocity, frequency and wavelength is v = f * lambda. You have v, and you've been given the frequency (it's 1/T where T = period). Plug them in. To answer c, you've apparently also been given a general expression for a traveling wave in terms of amplitude (known) and frequency or period (given) and an unknown offset, the only variable. Plug in the known quantities and solve for that unknown.