In the future, people will only enjoy one sport: electrodes. in this sport, you gain points when you cause metallic discs hovering on a field to exchange charge. you are an electro disc player playing the popular four disc variant. the disks have charges of qa = −8.0 µc, qb = −2.0 µc, qc = +5.0 µc, and qd = +12.0 µc. (a) you bring two disks together and then separate them. you measure the resulting charge of these two disks and find that it is +8.5 µc per disk. which two disks did you bring together

Explanation:

The total charge in the disks

must be conserved before and after bringing them together.

Lets equate the sum of the initial charge with the sum of the final for the disk:

So, the initial charges must sum +17 μC.

Now, as there are no charges over +17 μC, this means that both charges must be positive.

As the only positive charges are and , this disk must be the ones we are looking for. And, as we can see, they sum 17 μC:

what was the acceleration of the 2 kg cart?

⇒ 16.0 cm/s2

what was the acceleration of the 4 kg cart?

⇒ 8.1 cm/s2

what was the acceleration of the 6 kg cart?

⇒ 5.3 cm/s2

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