9. at the amusement park, a blue bumper car crashes into a red bumper car. which of the
following statements about their momentum is accurate?
a. there is less overall momentum after the collision.
b. the momentum of the red car is destroyed as it is hit.
c. there is greater overall momentum after the collision.
d. the overall momentum stavs the same before and after the collision

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.)