Applied Mechanics and Graphic Statics
The following is not a law of static friction:

The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces
The force of friction depends upon the roughness of the surface
The force of friction always acts in a direction opposite to that in which the body tends to move
The force of friction is dependent upon the area of contact

ANSWER DOWNLOAD EXAMIANS APP

Applied Mechanics and Graphic Statics
‘ω’ rad/sec is the angular velocity of a crank whose radius is ‘r’. If it makes θ° with inner dead centre and obliquity of the connecting rod ‘l’ is ‘ϕ’, the velocity v of the piston, is given by the equation

ω² (l sin ϕ - r cos θ tan ϕ)
ω² (l sin ϕ + r cos φ tan θ)
ω (l sin ϕ + r cos ϕ tan θ)
ω² (l cos ϕ + r sin ϕ tan θ)

ANSWER DOWNLOAD EXAMIANS APP