Consider a rubber ball which has an efficiency in one bounce of 34%. (That means 34% of the kinetic energy before the bounce remains kinetic energy after the bounce, while the rest of the energy is converted to thermal energy.) If the ball drops from a height of 7 m, then how high does it bounce back on the first bounce? Group of answer choices

9.4 m

7.0 m

4.6 m

1.9 m

2.4 m

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.)