a concrete brick is placed on a polished wood board which is initially laying horizontally on the floor. the static coefficient of friction is 0.63 between the board and the brick. the kinetic coefficient of friction is 0.55 between the two surfaces. we gradually raise one end of the wood board so that the board is tilted to increasingly larger angles, θ, relative to the horizontal. calculate the critical angle, θcrit at which the brick will start to slide along the wood board.

photocells convert light energy to electricity

as we probably am aware that our atmosphere or air have various levels, each level has different gasses, and each gas has another porousness. at the point when the light originates from lower porousness to higher penetrability, it alters its course. with the goal that implies that when the light originates from the moon to the earth, it alters it's course a lot more occasions. it essentially implies that the state of the light piece of the moon is changed on the earth.

not copied too! hope this !

joke:

h o h o hope you have a merry christmas!