Friction is the "evil" of all motion. No matter which direction something moves in, friction pulls it the other way. Move something left, friction pulls right. Move something up, friction pulls down. It appears as if nature has given us friction to stop us from moving anything. Friction is actually a force that appears whenever two things rub against each other. Friction is a force which causes the motion between two surfaces to be reduced. [see below for a more general discussion/ mw] Friction happens because most surfaces are not perfectly smooth. Even a table top which may appear smooth has little bumps in it if you looked at it with a really good microscope. When two surfaces try to move past each other these little bumps collide and slow the motion of the surfaces down causing what we call friction. The rougher a surface is the more and bigger bumps it has and the more friction will affect it. Some examples of this are sliding a wood block down a ramp. If you slide a wooden block down a ramp it is slowed by friction. If you cover the block in sand paper (making it rougher) the block will slide slower because friction is slowing it down more. Friction also increases if you push the surfaces together more. So a full suitcase will have more friction opposing it's motion if you try to slide it across the floor than an empty one. Other examples of friction are very numerous because friction happens any time you move two surfaces that are touching. Try looking around your house and experimenting on your own with rough and smooth surfaces. The frictional force is also presumed to be proportional to the coefficient of friction. However, the amount of force required to move an object starting from rest is usually greater than the force required to keep it moving at constant velocity once it is started. Therefore two coefficients of friction are sometimes quoted for a given pair of surfaces - a coefficient of static friction and a coefficient of kinetic friction. The force expression above can be called the standard model of surface friction and is dependent upon several assumptions about friction. Kinetic Friction is when two surfaces are moving with respect to one another, the frictional resistance is almost constant over a wide range of low speeds. It also is the force of friction that allows you to provide less force to an object to keep it from moving or to make it move. Coefficient of Friction that is friction is typically characterized by a coefficient of friction which is the ratio of the frictional resistance force to the normal force which presses the surfaces together. In this case the normal force is the weight of the block. Typically there is a significant difference between the coefficients of static friction and kinetic friction. Normal Friction is frictional resistance forces are typically proportional to the force which presses the surfaces together. This force which will affect frictional resistance is the component of applied force which acts perpendicular or "normal" to the surfaces which are in contact and is typically referred to as the normal force. In many common situations, the normal force is just the weight of the object which is sitting on some surface, but if an object is on an incline or has components of applied force perpendicular to the surface, then it is not equal to the weight. A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is an interaction between two objects, there is a force upon each of the objects. When the interaction ceases, the two objects no longer experience the force. Forces only exist as a result of an interaction. Forces can be measured using a device called force meter. The unit of force is called the newton. IForces resulting from physical interaction are called 'Contact Forces' and examples include Frictional, Tension, Air resistance and Spring force.A force resulting from non-physical interaction is…
product of force and distance. Energy is used every day and everywhere. The nuclear reactions in the sun releases heat light and other electromagnetic energy. Corn uses that energy to grow. The corn stores chemical metabolic energy. When the chicken eats the corn it stores energy in itself. When we chicken we store energy inside of us. Then we use metabolic energy and turn it into mechanical energy by pedaling a bike up a hill. The pedaling of the bike turns into kinetic energy. Kinetic energy is…
Faculty of Applied Science and Technology (FAST)
APPLIED MECHANICS 2 – ENGI 13386(FALL 2014)
Lab Report 3
Class: 1149_40517 (Group Number: 6)
Authors: Paritosh Chahal, Sandeep Sidhu, and Rony George
Date of Experiment: 8th October 2014
28 October 2014 – 6 pm
Instructor M. Arthur
Signed Declaration: the work submitted here is my own and not copied or plagiarized from another source.
Heat and Energy
February 7, 2013
The purpose of this paper is to discuss how the study of heat relates to the kinetic energy theory of matter. I will discuss what heat and temperature are, the relationship between them and their differences. I will provide examples of the various properties of a substance that will determine its heat capacity and various sources of heat.
In the 1840s scientists understood that heat was not just a substance but a…
determine how a mass m moves when a force (or forces) is applied. Newton’s First Law is: an object which moves at a constant velocity will continue moving at the same velocity unless it is acted upon by an non-zero force. The force could be a single force, or several forces which are unbalanced (don’t add to zero). Note that an object at rest has a constant velocity of zero, so it will remain at rest unless acted upon by such a force. Newton’s Second Law is: the force on a mass equals the mass multiplied…
We learn about friction in this lab. To purpose of the lab was to investigate the coefficient of friction for a given surface and the effects of factors such as weight have on the coefficient of friction. In order for us to test the varying Static friction or Kinetic friction we used an inclined plane, some wooden carts, and a masses, mass hanger, string, timer and a balance. The actual experiment consisted of two parts. The first part measured the net force, or more…
Passive vibration absorber with dry friction
A. Hartung, H. Schmieg, P. Vielsack
Summary The properties of a passive vibration absorber with dry friction signi®cantly differ from those of the classical linear absorber. The exceptional phenomenon is the possibility of suppressing all excited modes. This effect is in¯uenced to a small extent by a special shape of the friction characteristic, but mainly by an appropriately adjusted threshold of the static friction. The theoretical predictions are con®rmed…
Don't even think of memorizing anything in this table!
m (coefficient of friction)
oak on oak, dry
steel on steel, dry
steel on steel, greasy
steel on ice
rubber on asphalt, dry
rubber on asphalt, wet
rubber on concrete, dry
rubber on concrete, wet
rubber on ice
leather on oak, dry
1. A 70.0 kg hockey player glides across the ice on steel skates. What is the force of friction acting on his skates?
2. The driver of a 1.50 x…
first law which states an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. It is the characteristics of an object, with mass to resist motion and to stop or slow down when in motion.
Inertia is used to resist a force, resist the motion of an object, to allow specific motion etc. In the case of motor vehicles inertia is often used for example: When a vehicle accelerates, you feel as if your…
Friction Lab Report
To find the relationship between maximum static friction and normal force.
The relationship between maximum static friction and normal force is a direct positive linear relationship.
**Mass of Block: 95.8
Mass (kg) | Fsmax (N) | Fnorm (N) | Fsmax/Fnorm (N/N) |
.0958 | .5665 | 0.939 | 0.603 |
.1458 | .5964 | 1.429 | 0.4174 |
.1958 | .6562 | 1…
Static and Kinetic Friction
The amount of friction force between two surfaces in contact depends on the type of the surfaces in contact and the amount of compression between the surfaces. Static friction is the force that is acting against your force before the object begins to move. If you exert a small push on the box, the box will not move because static friction is directly opposite to the push. If you apply a greater force than the static friction force, the friction increases…