There are a lot of different types of forces that apply in the world around us. All of which are essential to our every day life. None more so that the Normal Force and Frictional Force which enables us all to walk and move around the Earth. In this video we talk about the Normal Force, how it is perpendicular to the surface that the object feeling the force is on and how it is a reactionary force to the force due to gravity but not always equal to the full force of gravity.
The second force we will talk about in this section is Frictional Force, which is a reactionary force to the motion of an object or forces that are trying to begin the motion of an object. We find the frictional force can be broken down into two different types: Static and Kinetic. Static frictional force is always greater than kinetic frictional force. We find that materials have different coefficients of friction depending on the materials that are in contact with each other. So wood and plastic will have a different coefficient of friction than wood and rubber. The coefficients for wood on plastic will be different depending on whether there is movement or the objects are static (again the difference between static and kinetic friction). We also find out that the Normal force has a big influence on the size of the frictional force.
Trinity Walton Club Activity Archive 