On the ladder resting on the ground and leaning against a smooth vertical wall, the force of friction will be_________________?

A. Downwards at its upper end
B. Upwards at its upper end
C. Perpendicular to the wall at its upper end
D. Zero at its upper end

Coefficient of friction is the_________________?

A. Angle between normal reaction and the resultant of normal reaction and the limiting friction
B. Ratio of limiting friction and normal reaction
C. The friction force acting when the body is just about to move
D. The friction force acting when the body is in motion

A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to________________?

A. W
B. W sin (a + $)
C. Wtan(a + <|))
D. W\an(a-)

If rain is falling in the opposite direction of the movement of a pedestrain, he has to hold his umbrella___________________?

A. More inclined when moving
B. Less inclined when moving
C. More inclined when standing
D. Less inclined when standing

A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t2 (t – 4), the acceleration of the particle will be given by the equation __________________?

A. 3t2-lt
B. 3t2+2t
C. 6f-8
D. 6f-4

A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is_______________?

A. 0°
B. 30°
C. 45°
D. 60°

Coulomb friction is the friction between _________________?

A. Bodies having relative motion
B. Two dry surfaces
C. Two lubricated surfaces
D. Solids and liquids

The effort required to lift a load W on a screw jack with helix angle a and angle of friction <j) is equal to _________________?

A. Wtan(a + )
B. Wtan(a-)
C. Wcos(a + )
D. Wsin(a + )

The maximum frictional force which comes into play when a body just begins to slide over another surface is called__________________?

A. Limiting friction
B. Sliding friction
C. Rolling friction
D. Kinematic friction

A single force and a couple acting in the same plane upon a rigid body_____________________?

A. Balance each other
B. Cannot balance each other
C. Produce moment of a couple
D. Are equivalent