Question

Spiders are especially sensitive to vibrations in their webs. The spectacular golden orb spiders monitors the radial threads of their webs for vibrations caused when an insects lands. The threads are made of silk with a linear density μ = 1.0 × 10-5 kg/m and the radial threads are and the 'inertial property' is the linear density of the thread. If an insect lands on the web 30 cm away from the spider, how long will it take for the spider to find out? (Ignore the spiders reaction time.) (3 marks)

Answer 1

v = speed of wave

T_s = tension force = 0.4 N

= 1 x 10^-5 kg/m

using the equation

v = sqrt(T_s /)

v = sqrt((0.4)/(1 x 10^-5))

v = 200 m/s

d = distance = 30 cm

time taken is given as

t = d/v = 30/200 = 0.15 sec