Give examples to show that friction is both a friend and a foe.

Explanation:

Wind resistance is a kind of friction we usually try to minimize.  It makes our cars and planes run less efficiently.  At the same time though, we need friction between our tires and the road to move, as well as friction in our brakes to stop.  We wouldn't be able to walk without friction, or start a campfire by rubbing sticks together.

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

vapour or gas assuming atmospheriv pressure