Pennies today are copper-covered zinc, but older pennies are 3.1 g of solid copper. What is the total positive charge in megacoloumbs (106 C) in a solid copper penny that is electrically neutral? The density of copper is 8900 kg/m^3.

total positive charge in one copper penny is 0.3 MC

Explanation:

As we know that the atomic number of copper is

z = 29

now moles of copper present in one copper penny is given as

now total number of copper atoms present in it

Now we know that in one atom there exist 29 protons and 29 electrons

so total positive charge in it

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.