towards the wall at its upper end

away from the wall at its upper end

upwards at its upper end

downwards at its upper end

downwards at its upper end

upwards at its upper end

perpendicular to the wall at its upper end

zero at its upper end

post friction

limiting friction

kinematic friction

dynamic friction.

angle between normal reaction and the resultant of normal reaction and the limiting friction

ratio of limiting friction and normal reaction

the friction force acting when the body is just about to move

the friction force acting when the body is in motion

proportional to normal load between the surfaces

dependent on the materials of contact surface

proportional to velocity of sliding

independent of the area of contact surfaces