Two boys are standing on a bridge 10 m above a stream. one boy throws a rock horizontally with speed of 5.0 m/s at exactly the same time that the other boy drops a rock vertically. which is true? a) a rock thrown horizontally strikes the water first b) a rock dropped vertically strikes the water faster c) both rocks strike the water at the same time d) none of the above

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.)