With an increase in angle of the inclined surface, the maximum angle at which a body starts sliding down the plane is called ___________.
angle of friction
Consider a block resting on a plane that is slowly tilted. Two forces act along the incline: the gravity component W sin θ pulling the block down the slope, and the friction force resisting it. Friction can rise only up to a maximum value, the limiting friction = μN = μ W cos θ, where μ is the coefficient of static friction.
As the angle θ increases, W sin θ grows while the maximum available friction μ W cos θ falls. At one particular angle they become equal and the block is just on the verge of sliding:
- W sin θ = μ W cos θ
- ⇒ tan θ = μ
This critical angle, whose tangent equals the coefficient of friction, is called the angle of friction (for loose granular material the same idea is called the angle of repose). It is the maximum inclination the surface can have before the body begins to slide, so it is the correct answer.
Static friction is the force that resists motion before sliding, not an angle. Limiting friction is the maximum value of that static friction force, again a force and not an angle. Cone angle belongs to the geometry of cone clutches/pulleys and is unrelated to sliding on an incline. Only the angle of friction correctly names the limiting inclination.
Similar Questions
A body is resting on a rough inclined plane. If the frictional force is equal to the component of weight along the plane, the body is in:
Which type of friction occurs when surfaces are lubricated with a fluid?
Under which scenario is a body on an inclined plane most likely to slip when subjected to a parallel force?
If a block slides down a rough plane inclined at 30° with a coefficient of friction of 0.2, the net acceleration is:
Which of the following is not a type of friction?
A block of weight (W) rests on a rough inclined plane with an angle of inclination α shown in the figure. The coefficient of friction between the block surface and the plane is μ, R is the normal reaction perpendicular to the inclined plane. A force (P) is applied parallel to the plane to prevent the block from sliding down. Which of the following represents the minimum value of (P) required to maintain equilibrium?
Important Questions from Friction
A steel wheel of 600 mm diameter rolls on a horizontal steel rail. It carries a load of 500 N. The coefficient of rolling resistance is 0.3 mm. The force in N, necessary to roll the wheel along the rail is:
Which of the following option is CORRECT about the methods used to reduce the friction?
Which of the following is NOT a law of static friction?
If we push the break of car then car will begin to slide when:
An elephant is stopped by a rope wound twice around the rough trunk of a tree. If the elephant exerts a pull of 1000 kgf, the minimum force required to stop the elephant is_________. (Coefficient of friction between the rope and the tree is 0.3)
