indentify friction as a force?

Question

i really did not even understand the question it is a for hw plz this was the last place i could turn to help

Answer 1

Frictional force is the force which opposes the relative motion of an object. It is directed opposite to the motion of an object. It is dependent on the coefficient of friction, and on the force applied on the object.

There are 3 types of frictional forces:

1. Static friction is the friction acting on a body when the body is not in motion, but when a force is acting on it. Static friction is the same as the force being applied (because the body isn't moving). Static friction acts because the body tends to move when a force is applied on it.
2. Limiting friction is the friction on a body just before it starts moving. Generally, limiting friction is the highest.
3. Kinetic friction is the friction which acts on the body when the body is moving. Kinetic friction is usually smaller than limiting friction.

Answer 2

By Newton's law, a body in motion should continue to be in uniform motion till a force acts on it.

But in every day life we see the other way. That is, if a ball is rolled on the ground soon it comes to rest. It seems that Newton’s law is not valid.
But a careful observation shows that some force between the ball and ground makes the ball to come to rest.

If the ball and ground are smooth enough the ball takes more time or moves more distance before coming to stop.

Thus we infer or identify this force as the force which changes the state of the motion of the body. We call this as force of friction.

Similarly when a stationary body is pushed or pulled by small force the body is not moving. But by Newton's law it must move, whatever is the magnitude of the force. Again we infer that some force which we call static friction is the reason for this.

Answer 3

Let's talk in terms of vectors. You have a box and you push it forward. You are applying force to the box so it moves forward. Now, the box is pretty heavy and because it is touching the ground, it is not so easy to move it. Friction is acting against the force you are applying to move the box. Therefore, in terms of vectors, in this case the force applied goes one way, while the friction caused by the ground, on the box, is a vector force applyied the opposite way.

Answer 4

friction is a force caused by objects rubbing against other objects. The coefficient of friction measures how much friction exists. The higher the coefficient, the more friction exists.