A particular Alnico (aluminum, cobalt, nickel, and iron) bar magnet (magnet A) has a mass of 10 g. It produces a magnetic field of magnitude 6e-05 T at a location 0.18 m from the center of the magnet, on the axis of the magnet.

(a) Approximately what is the magnitude of the magnetic field of magnet A a distance of 0.36 m from the center of the magnet, along the same axis?

|A| = T

(b) If you removed the original magnet, and replaced it with a magnet made of the same material, but with a mass of 30 g (magnet B), approximately what would be the magnetic field at a location 0.18 m from the center of the magnet, on the axis of the magnet?

|B| = T

Researchers conducted an experiment to identify the effects of three different hand sanitizers on the growth of bacteria. the researchers grew one type of bacteria in twenty-four identical covered petri dishes. then, they opened eighteen petri dishes and applied the three hand sanitizers to six petri dishes each. they left the remaining six petri dishes closed as a control group. when the researchers measured the growth of bacteria two days later, the six dishes that had no hand sanitizer showed the least amount of bacterial growth. the researchers concluded that not using any hand sanitizer would lead to the least bacterial growth. which statement best explains why the researchers’ conclusion was not justified? the experiment tested too many variables. the control group was not treated the same as the experimental group. the sample size of twenty-four petri dishes is not large enough. the single type of bacteria is not adequate to make any conclusions.