During the formation of the aurora borealis, the electrons in an atom experience a change in energy levels. Which statement about this change is accurate? First, the electron releases energy to move to a higher energy level.

First, the electron absorbs energy to move to a higher energy level.

First, the electron absorbs energy to move to a lower energy level.

First, the electron releases energy to move to a lower energy level.

What is the temperature in degrees celsius of a substance with a tempature of 49k

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f