a(t) = 210 - 5t
(1) What does t represent?
Since t is given in minutes, it stands for time.
Interpreting t as the balloon’s altitude is incorrect since a(t) represents altitude.
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Time elapsed since the balloon starts descending
This is the correct interpretation.
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Time for the balloon to reach ground level is incorrect because that would be a fixed moment, not a variable t.
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(2) What does a(t) represent?
The balloon’s altitude
This is the correct answer.
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Time since descent began is incorrect because that is represented by t.
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Time to reach the ground is inaccurate since a(t) is altitude, not time.
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(3) What does a(5.5) signify?
It does not represent the time to reach 5.5 feet altitude.
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The altitude of the balloon after 5.5 minutes
This is the correct interpretation since a(5.5) is altitude when t = 5.5 minutes.
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It is not the time needed to reach the ground.
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5.5 minutes alone is not correct because a(t) denotes altitude, not time.
a(5.5) refers to altitude at t = 5.5 minutes.