The resultant of the following three couples 20 kg force, 0.5 m arm, $ ve sense 30 kg force, 1 m arm, – ve sense 40 kg force, 0.25 m arm, + ve sense having arm of 0.5 m will be_________________?

A. 20 kg, – ve sense
B. 20 kg, + ve sense
C. 10 kg, + ve sense
D. 10 kg, – ve sense

The coefficient of friction depends on_________________?

A. Area of contact
B. Shape of surfaces
C. Strength of surfaces
D. Nature of surface

The ratio of limiting friction and normal reaction is known as_______________?

A. Coefficient of friction
B. Angle of friction
C. Angle of repose
D. Sliding friction

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

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

Frictional force encountered after commencement of motion is called________________?

A. post friction
B. limiting friction
C. kinematic friction
D. frictional resistance

Pick up wrong statement about friction force for dry surfaces. Friction force is________________?

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

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

Tangent of angle of friction is equal to_________________?

A. Kinetic friction
B. Limiting friction
C. Angle of repose
D. Coefficient of friction