Apogo stick has a spring with a force constant of 2.50 × 104 n/m , which can be compressed 11.2 cm. what maximum height, in meters above the compressed position of the spring, can a child jump with the stick using only the maximum elastic potential energy in the spring, if the child and stick have a combined mass of 44 kg?

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.)