Friction - AJ

• Friction is a force that acts to stop the movement of two touching things. The energy lost to friction is turned into sound and heat.
• Two different types of frictions are called Static and Kinetic. Static friction is when friction is strong enough that it is able to stop the movement between two objects. Kinetic friction is when frictional force is not strong enough to stop all motion.
• Friction can be thought to be caused by bumps on two touching surfaces.
  These types of bumps are called asperities.
• As the force that is pushing on an object increases, the static Friction increases too. However, if the force gets bigger than the maximum static Friction, it begins to make the object accelerate.
• Friction is actually caused by electromagnetism. When the atoms that make the objects come close they are drawn to each other and they may connect.