A84-kg hiker starts at an elevation of 1500 m and climbs to the top of a 3100-m peak. what is the hikers change in potential energy?

Light that is polarized along the vertical direction is incident on a sheet of polarizing material. only 96% of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. no light passes through the second sheet. what angle does the transmission axis of the second sheet make with the vertical?

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.

Lacie kicks a football from ground level at a velocity of 13.9 m/s and at an angle of 25.0° to the ground. how long will the ball be in the air before it lands? round your answer to the nearest tenth. s how far will the football travel before it lands? round your answer to the nearest tenth. m