An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
The total charge delivered by the device is 450 coulombs. This corresponds to approximately 2.81 x 10^21 electrons flowing through it in 30 seconds. Thus, a large number of electrons move through the device when current passes.
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The use of semi-colons can be a bit tricky, but they are incredibly useful for connecting related independent clauses in a clear manner. Let's discuss each sentence step-by-step:
Sentence A: 'Their best player has moved to another team; he will be greatly missed.'
In this sentence, two independent clauses ('Their best player has moved to another team' and 'he will be greatly missed') are connected with a semi-colon. This is appropriate because both clauses are closely related and could stand alone as separate sentences.
Sentence B: 'We did our very best to save the old building from demolition. We sent a letter of protest to the council; we sought the help of our local MP; we launched a protest campaign; we collected hundreds of signatures from fellow objectors; and we held demonstrations outside the town hall.'
In the second part, a series of actions is described. The semi-colons are used to separate the complex list of actions taken to prevent the demolition. Each action: 'sent a letter,' 'sought help,' 'launched a campaign,' 'collected signatures,' 'held demonstrations' is an independent clause linked by semi-colons.
Sentence C: 'The members of the choir had all practiced very hard before the competition; sadly, they came last.'
This sentence uses a semi-colon because it connects two related independent clauses: the effort put in by the choir and the disappointing result.
Sentence D: 'We visited many historical sites in Britain. We went to the Tower of London; the Houses of Parliament in London; some of the colleges at Oxford; Durham Cathedral; the historical cities of Chester and York.'
Similar to sentence B, this sentence uses semi-colons to separate a list of places visited. The use of semi-colons helps to clarify the list, especially since some list items—like 'the historical cities of Chester and York'—already contain commas.
In summary, semi-colons can be used to join independent clauses that are linked in meaning and to separate complex list items that have internal punctuation. This helps in making sentences clearer and more structured.
