A. towards the wall at its upper end
B. away from the wall at its upper end
C. upwards at its upper end
D. downwards at its upper end
E. none of the above
A. post friction
B. limiting friction
C. kinematic friction
D. frictional resistance
E. dynamic friction
A. proportional to normal load between the surfaces
B. dependent on the materials of contact surface
C. proportional to velocity of sliding
D. independent of the area of contact surfaces
E. none of the above is wrong statement
A. 3t2-lt
B. 3t2+2t
C. 6f-8
D. 6f-4
E. 6t2-8t
A. 0°
B. 30°
C. 45°
D. 60°
E. 90°
A. bodies having relative motion
B. two dry surfaces
C. two lubricated surfaces
D. solids and liquids
E. electrically charged particles
A. kinetic friction
B. limiting friction
C. angle of repose
D. coefficient of friction
E. friction force
A. Wtan(a + )
B. Wtan(a-)
C. Wcos(a + )
D. Wsin(a + )
E. W (sin a + cos )
A. r/2
B. r/A
C. r/%
D. 0.134 r
E. 3r/8
A. balance each other
B. cannot balance each other
C. produce moment of a couple
D. are equivalent
E. none of the above