The blame has been pinned, squarely and often, on inadequate oversight of U.S. financial institutions, which created ever more complex and risky mortgage instruments, lured people to buy homes they could not afford, and brought the economy crashing to the ground.
Motion on the Earth does not take place in a vacuum. When one thing moves, it moves through or across another. When a wheel turns on an axle, the two surfaces rub against one another. This is called dry friction. Grease can be used to separate the solid metal parts, but this just reduces the problem to layers within the grease sliding past one another.
As seen in the above diagram, when an object is on an inclined plane, gravity is not acting perpendicular to the sliding surfaces. In this case only a portion of the objectâs weight would act as normal force. TRACTION: TRACTION can be defined as the friction between a drive wheel and the surface it moves upon. It is the amount of force a wheel can apply to a surface before it slips.