In the direction opposite to that of the sliding body.
Kinetic friction is the friction that applies when an object is moving; static friction is the friction that applies when the object is not moving. Static friction must always be greater than, or equal to, kinetic friction.
opposing the motion
If the surface is smooth then it is almost frictionless. Hence the body will continue to move with constant velocity. However the object continues in a circular path and the weight is thus the centripetal force. It is assumed that the surface is very large)
The value of the friction force will increase to match and oppose the external force up to a maximum value known as the static friction force. Once the external force exceeds the maximum static friction force, the object will begin to move, and the friction force will decrease to the kinetic friction force, which is generally lower than the maximum static friction force.
The force acting on a free falling body, neglecting air friction, is solely the force of gravity. This force causes the body to accelerate downward at a rate of 9.8 m/s^2 (or 32 ft/s^2) until it reaches terminal velocity or impacts the ground.
limiting friction is force of friction when a body slides over the surface of another body
When a body slides or rolls over another body, the force of friction is called kinetic friction. This friction arises due to the contact between the surfaces of the two bodies and opposes the relative motion between them.
The direction of friction of a rolling body is in opposite direction to the motion of the rolling body.
Kinetic friction is the friction that applies when an object is moving; static friction is the friction that applies when the object is not moving. Static friction must always be greater than, or equal to, kinetic friction.
opposing the motion
The direction of friction on a rotating object in a clockwise direction depends on the point of contact. Friction opposes the relative motion between the object and the surface it is in contact with, so the direction of friction will act in the direction opposite to the slipping or sliding motion at that contact point.
For a force to do work on a body, the force must cause the body to move in the direction of the force. Work is defined as the product of the force applied and the distance over which the force is applied in the direction of the force.
Friction is the force exerted on a body when the body pushes against the microscopic obstacles in its path. Therefore , it is basically a reaction to the force exerted by the body.It comes into play when a body moves on a surface which is not completely even ,even at the microscopic level. Another difference is that the friction force is constant beyond a threshold for a given homogeneous surface,even if we increase speed of the body. Friction is essential for our movement and to keep in place things such as a knot. The resisting force employed usually by the resisting obstacles is the electromagnetic force.
Due to friction velocity of a body gets reduced, reduction in velocity causes change in velocity. This change in velocity leads to production of acceleration.(Because only acceleration can produce change in velocity either its direction or its magnitiude). And only a force can cause the acceleration hence friction is a force.
Due to friction velocity of a body gets reduced, reduction in velocity causes change in velocity. This change in velocity leads to production of acceleration.(Because only acceleration can produce change in velocity either its direction or its magnitiude). And only a force can cause the acceleration hence friction is a force.
The frictional force on a sliding body on a plane will be acting parallel to the plane against the motion of the body. But the magnitude of the (kinetic) friction force is proportional to the weight component normal to the plane. The weight component parallel to the plane is the force that tends to slide the body down the inclined plane. When the sliding body has acquire steady velocity, the friction force is equal to the body's sliding force.
It depends on how the axes are defined. If the for motion in one dimension, if the positive direction is defined direction of motion, then yes, because friction opposes motion. If the motion is in two or three directions, then the force of friction is a vector and, strictly speaking, neither positive not negative. The sign (if any) of any force is arbitrary, as long as all forces in the diagram use the same frame of reference.