Examples of frictional force in the following topics:
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- Recall that the force of friction depends on both the coefficient of friction and the normal force.
- As always, the frictional force resists motion.
- If the maximum frictional force is greater than the force of gravity, the sum of the forces is still 0.
- The force of friction can never exceed the other forces acting on it.
- The frictional forces only act to counter motion.
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- Another type of frictional force is static friction, otherwise known as stiction.
- Like kinetic friction, the force of static friction is given by a coefficient multiplied by the normal force.
- In general, the force of static friction can be represented as:
- As with all frictional forces, the force of friction can never exceed the force applied.
- Any force larger than that overcomes the force of static friction and causes sliding to occur.
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- The force of friction is what slows an object sliding over a surface.
- The force of friction can be represented by an equation: $F_{\text{friction}} = \mu F_n$.
- $F_n$ is called the normal force and is the force of the surface pushing up on the object.
- Frictional forces always oppose motion or attempted motion between objects in contact.
- Much of the friction is actually due to attractive forces between molecules making up the two objects, so that even perfectly smooth surfaces are not friction-free.
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- External forces: forces caused by external agent outside of the system.
- There are mainly three kinds of forces: Gravity, normal force (between ice & pucks), and frictional forces during the collision between the pucks
- With this in mind, we can see that gravity and normal forces are external, while the frictional forces between pucks are internal.
- Without knowing anything about the internal forces (frictional forces during contact), we learned that the total momentum of the system is a conserved quantity (p1 and p2 are momentum vectors of the pucks. ) In fact, this relation holds true both in elastic or inelastic collisions.
- (neglecting frictional loss in the system. )
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- Net force affects the motion, postion and/or shape of objects (some important and commonly used forces are friction, drag and deformation).
- Specifically, we will discuss the forces of friction, air or liquid drag, and deformation.
- Friction is a force that resists movement between two surfaces sliding against each other.
- Friction is not itself a fundamental force, but arises from fundamental electromagnetic forces between the charged particles constituting the two contacting surfaces.
- Like friction, the force of drag is a force that resists motion.
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- Conservation of mechanical energy states that the mechanical energy of an isolated system remains constant without friction.
- Conservation of mechanical energy states that the mechanical energy of an isolated system remains constant in time, as long as the system is free of all frictional forces.
- In any real situation, frictional forces and other non-conservative forces are always present, but in many cases their effects on the system are so small that the principle of conservation of mechanical energy can be used as a fair approximation.
- Now, if the conservative force, such as the gravitational force or a spring force, does work, the system loses potential energy (PE).
- Remember that the law applies to the extent that all the forces are conservative, so that friction is negligible.
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- Ff: the friction force of the ramp.
- There is a potential difficulty also with the arrow representing friction.
- Now, the tip of the friction arrow is at the highest point of the base.
- The engineer in this instance has assumed a rigid body scenario and that the friction force is a sliding vector and thus the point of application is not relevant.
- These forces can be friction, gravity, normal force, drag, tension, etc...
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- In the presence of dissipative forces, total mechanical energy changes by exactly the amount of work done by nonconservative forces (Wc).
- Here we will adopt the strategy for problems with dissipative forces.
- Using energy considerations, calculate the distance the 65.0-kg baseball player slides, given that his initial speed is 6.00 m/s and the force of friction against him is a constant 450 N.
- Strategy: Friction stops the player by converting his kinetic energy into other forms, including thermal energy.
- The work done by friction is negative, because f is in the opposite direction of the motion (that is, θ=180º, and so cosθ=−1).
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- In an "ideally banked curve," the angle $\theta$ is chosen such that one can negotiate the curve at a certain speed without the aid of friction.
- In an "ideally banked curve," the angle $\theta$ is such that you can negotiate the curve at a certain speed without the aid of friction between the tires and the road.
- For ideal banking, the net external force equals the horizontal centripetal force in the absence of friction.
- The only two external forces acting on the car are its weight $w$ and the normal force of the road $N$.
- Friction helps, because it allows you to take the curve at greater or lower speed than if the curve is frictionless.
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- The unemployment rate is a percentage, and calculated by dividing the number of unemployed individuals by the number of all currently employed individuals in the labor force.
- Frictional unemployment is another type of unemployment within an economy.
- Frictional unemployment is always present to some degree in an economy.
- Frictional unemployment is influenced by voluntary decisions to work based on each individual's valuation of their own work and how that compares to current wage rates as well as the time and effort required to find a job.
- The natural rate of unemployment is a combination of structural and frictional unemployment.