Final answer:
When two identical conducting spheres are brought into contact, their charges redistribute themselves so that they have the same charge.
Step-by-step explanation:
When two identical conducting spheres are brought into contact, the charges on the spheres redistribute themselves so that they have the same charge. For example, if one sphere has a charge of +5μC and the other sphere has a charge of +1μC, after they touch, the charge is redistributed and each sphere will have a charge of +3μC.
Next, one of the spheres that now carries a charge of +3μC is brought into contact with the third sphere that carries a charge of -7.20μC. After they separate, the charge is redistributed again so that each sphere will have half of the total charge. In this case, the final charge on the third sphere is -3.60μC. After they touch, each sphere will have half of the total original charge. When one of these spheres is brought into contact with a third sphere, the charges redistribute again so that each sphere will have half of the total charge.
When identical conducting spheres are brought into contact, they share their charges equally due to the principle of charge conservation. In the case of the three metallic spheres with charges q₁=+5.40μC, q₂=+1.40μC, and q₃=−7.20μC, we first combine q₁ and q₂. The combined charge will be (+5.40μC + +1.40μC) divided by 2, yielding a new charge on each sphere of +3.40μC after they are separated.
Next, when one of these spheres is brought into contact with the third sphere q₃, we have to combine the charges and then divide by two again. So, the combination of +3.40μC and −7.20μC results in a total charge of −3.80μC. Splitting this charge between the two spheres gives −1.90μC for the final charge on the third sphere.