Pushing a heavy rock
No friction is not always bad. In fact consider an example of running on wet floor. If there is too little friction it might cause you to slip and slide.
bad friction is when 2 things rub together .
Friction isn't always bad, but when engineers try to avoid or reduce friction, it is because of the energy lost due to friction.
An example of a non-frictional force is gravitational force. For example, when an object is in free fall, there is no friction acting on it.
Some machines need friction to operate. Brakes, grinders, traction wheels, and others all rely on friction to work. In other cases, friction is bad. electric and fuel-fired powerplants for example, are all designed so as to minimize friction. That's why the lubricant industry exists!
An example of fluid friction is the air resistance felt by an airplane.
Tires skidding on a wet road due to lack of traction. Trying to push a heavy object across a rough surface with a lot of resistance. Rubbing two rough surfaces together, causing heat and wear on the materials involved.
A example of friction is rubbing your hands together the heat you feel is friction. Oh dont be a shat head.
Rolling Friction, Static Friction, Sliding Friction, & fluid Friction
A piece of sand paper on a piece of wood is an prime example of rubbing friction.
Friction is good because it provides traction. Friction is necessary for people to stand, or for vehicles to accelerate or break. Friction can also be used to convert kinetic energy to heat or electrical energy. Friction can be bad because kinetic energy is can be lost to friction.
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