Young david who slew goliath experimented with slings beforetackling the giant. he found that he could revolve a sling oflength 0.600 m at the rate of9.00 rev/s. if he increased the lengthto 0.900 m, he could revolve the slingonly 7.00 times per second.(a) what is the speed of the stone for eachrate of rotation? 1 m/s at 9.00 rev/s2 m/s at 7.00 rev/s(b) what is the centripetal acceleration of the stone at9.00 rev/s? 3 m/s2(c) what is the centripetal acceleration at 7.00 rev/s? 4 m/s2

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)