Two forces F1 and F2 are acting on a block of mass m=1.5 kg. The magnitude of force F1 is 12N and it makes an angle= 37degree with the horizontal as shown in
figure-1. The block is sliding at a constant velocity over a frictionless floor. (a) Find the value of the normal force on the block. Find the magnitude of force F2 that is acting on the block. (c) Find the magnitude of force ~F2 if the block accelerates with a magnitude of a = 2:5 m=s2 along the direction of F2

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.