nivek114 said:1. Why do we use static friction instead of kinetic friction for a rolling object?
nivek114 said:2. Why do we ignore the effects of friction in the conservation of energy?
Friction is a force that resists the relative motion of two surfaces in contact with each other. It is caused by the irregularities in the surfaces of objects that come into contact with each other.
Friction is measured using a unit called coefficient of friction. It is a dimensionless number that represents the ratio of the force required to move an object across a surface to the force pressing the two surfaces together.
The amount of friction between two surfaces is affected by the nature of the surfaces, the force pressing them together, and the presence of any lubricants or contaminants. Rough surfaces have higher friction than smooth surfaces, and increasing the force pressing the surfaces together increases the amount of friction.
Friction can either help or hinder motion. When trying to move an object, friction acts in the opposite direction and makes it harder to move. However, friction also helps us walk, drive, and grip objects by providing traction.
Friction can be reduced by using lubricants like oil or grease between surfaces, making surfaces smoother, or by reducing the force pressing the surfaces together.