Static Friction
Static Friction: Overview
This Topic covers sub-topics such as Static Friction, Coefficient of Static Friction, Limiting Friction Force and, Dependence of Static Friction Force on Various Factors
Important Questions on Static Friction
Consider a car moving along a straight horizontal road with speed of . If the coefficient of static friction between the tyres and the road is , the shortest distance in which the car can be stopped is (taking )

A heavy uniform chain lies on a horizontal table-top. If the coefficient of friction between the chain and the table surface is , then the maximum fraction of the length of the chain that can hang over one edge of the table is

The coefficient of static friction, between block of mass and the table as shown in the figure is . The maximum mass value of block so that the two blocks do not move is (The string and the pulley are assumed to be smooth and massless

A block of mass rests on a rough inclined plane making an angle of with the horizontal. The coefficient of static friction between the block and the plane is The frictional force on the block is

An insect crawls up a hemispherical surface very slowly (see the figure). The coefficient of friction between the insect and the surface is . If the line joining the center of the hemispherical surface to the insect makes an angle with the vertical, the maximum possible value of is given by,

A block rests on a rough inclined plane making an angle of with the horizontal. The coefficient of static friction between the block and the plane is . If the frictional force on the block is , the mass of the block (in ) is (take: ),

A block of mass lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is . If the acceleration of the truck is . Find the frictional force acting on the block.

A block with mass is resting on another block of mass As shown in figure, a horizontal rope tied to a wall holds it. The coefficient of friction between and is while coefficient of friction between and the ground is The minimum required force to start moving will be

The magnitude of frictional force acting between the block and the inclined plane, as shown in the figure, is (take )

For a truck with tyres, only rear wheels are power driven and can produce acceleration. These wheels support half the entire load. If the coefficient of friction between road and each tyre is , the maximum attainable acceleration by this truck would be (Acceleration due to gravity )

Sand is to be piled up on a horizontal ground in the form of a regular cone of a fixed base of radius . Coefficient of static friction between the sand layers is . Maximum volume of the sand that can be piled up in the form of cone without slipping on the ground is

A block of mass lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is . If the acceleration of the truck is The frictional force acting on the block is:

`An object of is in the state of limiting equilibrium on an inclined plane having angle of inclination Now if the angle of inclination is increased to then the extra force along the plane to be applied on the object, to keep it in equilibrium will be (take )

Find the minimum value of so that the block do not move :-

Find the acceleration of body as shown in figure. If friction is present between only and applied force is less than limiting friction.

For next three question please follow the same
An engineer is designing a conveyor system for loading lay bales into a wagon. Each bale is 0.25 m wide, 0.50 m high, and 0.80 m long (the dimension perpendicular to the plane of the figure), with mass 30.0 kg. The center of gravity of each bale is at its geometrical center. The coefficient of static friction between a bale and the conveyor belt is 0.60, and the belt moves with constant speed. The angle of the conveyor is slowly increased. At some critical angle a bale will tip (if it doesn't slip first), and at some different critical angle it will slip (if it doesn't tip first).

Find the second critical angle (in the same conditions) at which it slips.

A car begins from rest at time , and then accelerates along a straight track during the interval s and thereafter with constant velocity as shown in the graph. A coin is initially at rest on the floor of the car. At , the coin begins to slip and its stops slipping at. The coefficient of static friction between the floor and the coin is ()

In the figure The coefficient of friction between man and ground is , between and ground is , between and is . What will be the tension in string between man and block when the man is pulling with maximum possible force such that the system is stationary?

A block of mass is acted upon by a force at an angle with the horizontal in a downward direction. Let the coefficient of friction between the block and the horizontal surface is. What will be the friction force acting on the block by the ground? :

Let the coefficient of friction between wedge and block be what will be the maximum horizontal acceleration of the wedge for which block will remain at rest w.r.t. the wedge ?
