physics
posted by Marco .
A spider hangs from a strand of silk whose radius is 4.40 106 m. The density of the silk is 1300 kg/m3. When the spider moves, waves travel along the strand of silk at a speed of 264 m/s. Determine the mass of the spider.

The speed of the wave can be related to the Tension (T) and density per length (d) of the strand. The formula is:
264 = sqrt(T/d)
d = pi*r^2*1300 = 7.9*10^8 kg/m
The tension T equals M g. Use that fact to compute the spider's mass, M.