Question

a swimming pool is an example of an open system. the pool loses 10,500 j of its thermal energy to the surrounding air at night, and the surrounding air adds 2,500 j of thermal energy to the pool in the morning. according to the law of conservation of energy, what is the total change in energy? a. an increase of 10,500 j b. a decrease of 13,000 j c. an increase of 2,500 j d. a decrease of 8,000 j

Explanation:

Step1: Determine the sign of energy change

Losing energy is negative, so losing \(10500\ J\) is \(- 10500\ J\). Gaining energy is positive, so gaining \(2500\ J\) is \(+2500\ J\).

Step2: Calculate the total change in energy

Use the formula \(\Delta E=-10500 + 2500\).

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Answer:

D. A decrease of \(8,000\ J\)