A housefly walking across a clean surface can accumulate a significant positive or negative charge. In one experiment, the largest positive charge observed was +73 pCpC. A typical housefly has a mass of 12 mgmg. How many electrons does it lose to the surface it is walking across?

Explanation:

Since the fly accumulated a positive charge of +73pC, it must have lost an equal number of negative charge of -73pC to the surface (because the housefly was neutral to begin with).

Therefore, to answer our question we have to ask ourselves how many electrons combine to make -73pC of charge?

The answer is since one electron carries a charge of , the number of electrons that make up -73pC are

Thus, the housefly lost about 456 million electrons to the surface!

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm