Web spiders and oscillations all spiders have special organs that make them exquisitely sensitive to vibrations. web spiders detect vibrations of their web to determine what has landed in their web, and where. in fact, spiders carefully adjust the tension of strands to "tune" their web. suppose an insect lands and is trapped in a web. the silk of the web serves as the spring in a spring-mass system while the body of the insect is the mass. the frequency of oscillation depends on the restoring force of the web and the mass of the insect. spiders respond more quickly to larger - and therefore more valuable - prey, which they can distinguish by the web's oscillation frequency. suppose a 15 mg fly lands in the center of a horizontal spider's web, causing the web to sag by 4.0 mm .

assuming that the web acts like a spring, what is the spring constant of the web?

During physical science, ms. greene challenged her students to produce an energy transformation. james and jill wrapped a 4-inch nail with a coil of fifty turns of wire. they connected one end of the coil to one terminal of a knife switch. they connected the other terminal of the knife switch to the battery. finally, they connected the end of the coil to the other terminal of the battery. james held the tip of a 1-inch nail near the flat end of the 4-inch nail. jill closed the knife switch quickly and then opened it. the 1-inch nail was pulled toward the 4-inch nail. what is the best explanation of why the nail moved? a) electrical energy was converted to mechanical energy in the 1-inch nail. b) the 4-inch nail became an electromagnet and the magnetic force attracted the 1-inch nail. c) the electric current in the 4-inch nail was converted to mechanical energy in the 1-inch nail. d) the 4-inch nail had a positive charge and the 1-inch nail had a negative charge. opposites attracted.

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.