Posted by Marco on .
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.

physics 
drwls,
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.