Lab 106(P1) Static and Kinetic Frictions Name: Cristina Aponte Lab: Phys102A-003 Lab Group: Umaamah Tobias, Vincent Hu Date: 25th October, 2016 OBJECTIVES1.Measure the static and kinetic frictional forces using a force sensor 2.Determine the relationship between friction force and normal force acting on an object 3.Measure the coefficient of static friction and kinetic friction between surfaces. INTRODUCTION:Whenever the surface of one body slides over that of another, each body exerts a frictional force on the other, parallel to the surfaces. The direction of friction on each body is opposite to that of its motion relative to the other. An example: a block rests on a table with the gravitation force of the block balanced by a normal force of which direction is opposite to the gravitational force. Normal force is exerted on a body by a surface wherever the body is in contact with the surface of another body. You apply the force on the block by trying to pull it to the right until it slide. Responding to this force, a frictional force is exactly balancing your applied force, which is directed to the left. The frictional force here is called static frictional force. As one increases the applied force, a limiting point reaches where the block breaks away from the surface and begins to slide. This implies that there is a certain maximum value that the static frictional force can have. When the applied force is larger than the maximum static frictional force, the object begins to slide and you have to continue to exert force to keep that object sliding. The force acting on the object while it is sliding is called kinetic frictional force. You don't need to apply much force to keep the object sliding as needed to break free of static friction. The static frictional force between two surfaces can assume any value between zero and a maximum value. 1.0<fs<fsmax The static frictional force will = the maximum value fsmax, when a body is on the verge of sliding.