Whats the difference between the formulas for kinetic and static friction.
Kinetic:
Ff= ukFn
Static:
Ff= usFn
Are the 'f' and the 'n' the mass of the object?
Are the 'k' and the 's' just the
The f and the n are subscripts that stand for "friction" and "normal"
k and s are subscripts of "u" that denote "kinetic" and "static"
It is too bad that the computer tools available to us here do not permit subscripts.
to find the frictional force you would take the coefficient x the weight?
Ff is force friction. Fn is the normal force, not the mass of the object. The normal force does depend on the weight of an object, which ultimately depends on the mass.
Although there is no difference in the actual equations for physics, there is a difference between kinetic and static friction. Say if you start pushing a box, kinetic friction is the friction between between the ground and the box when the box is moving, and static friction is the friction you need to overcome to start moving the box.
Hope this helps!
Thanks Drwls & Carlie :)
In the formulas for kinetic and static friction, the variables represent the following:
- 'Ff' represents the force of friction acting between two surfaces in contact.
- 'uk' and 'us' are the coefficients of friction for kinetic and static friction respectively. These coefficients depend on the nature of the surfaces in contact and can vary from material to material.
- 'Fn' represents the normal force exerted on an object by a surface. This force is perpendicular to the contact surface and depends on the weight of the object or the force pushing it against the surface.
To clarify, neither 'f' nor 'n' represent the mass of the object; they represent the force of friction and the normal force respectively. The mass of the object does not directly affect the calculation of friction; it affects the normal force but not friction itself.
The main difference between the two formulas is that kinetic friction occurs when the surfaces are in relative motion, while static friction occurs when the surfaces are at rest or not moving relative to each other. The coefficient of kinetic friction ('uk') is generally lower than the coefficient of static friction ('us') for the same surfaces.