A box of mass 44 kg is pushed hard enough to set it in motion across a flat surface. The coefficient of kinetic friction between the box and the surface µk = 0.48. What minimum pushing force is needed to keep the box moving at a constant velocity? a 231n
b 207n
c 178n
d 283n

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current

An ascending elevator, hanging from a cable, is coming to a stop. part a part complete identify all forces acting on the elevator from the list below. select all that apply. select all that apply. kinetic friction normal force tension weight static friction submitprevious answers correct part b draw a free-body diagram of the object. draw the vectors starting at the black dot. the location and orientation of the vectors will be graded. the exact length of your vectors will not be graded but the relative length of one to the other will be graded.

The goal of this experiment was to answer the question, "how does diffraction occur? " suppose you formulated this alternate hypothesis: if the gap width is increased while keeping wavelength constant, then the observed diffraction will decrease because the less the ratio between wavelength and gap width is, the smaller the observed diffraction angle will be. to test this hypothesis, you would change the  gap widthdiffraction anglewavelength  and observe the  gap widthdiffraction anglewavelength  in the system. therefore, the independent variable would be the  gap widthdiffraction anglewavelength  and the dependent variable would be the  gap widthdiffraction anglewavelength.