Applied Mechanics and Graphic Statics The following statement is one of the laws of Dynamic friction

All of these
The force of friction always acts in a direction opposite to that in which a body is moving
For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed
The magnitude of the kinetic friction bears a constant ratio to the normal reaction between two surfaces. The ratio being slightly less than that in the case of limiting friction

Applied Mechanics and Graphic Statics The torque produced by a force depends on i. the magnitude of the force ii. the direction of the force iii. the point of application of the force relative to origin The correct answer is

both (i) and (ii)
both (i) and (iii)
only (i)
all (i), (ii) and (iii)

90°
60°
45°
30°

u² sin² α/2g
u² cos² α/2g
u² sin 2α/2g
u² tan² α/2g

Applied Mechanics and Graphic Statics The phenomenon of collision of two elastic bodies takes place because bodies

All listed here
Tend to compress each other till they are compressed maximum possible
Attempt to regain its original shape due to their elasticities
Immediately after collision come momentarily to rest

7.5 cm
8.75 cm
7.85 cm
5.0 cm