Final answer:
The energy content for a 2.00-W clock run over 18 months was incorrectly matched with any option provided; it should be 93,312,000 J. A battery with an energy supply of 8.00×104 J can run a 1.00×10−3 W pocket calculator for 8.00×107 seconds. Solar cells are suitable for low-energy devices like calculators. Thus, the correct answer in part (b) is 8.00×107 seconds.
Step-by-step explanation:
To determine the available energy content of a battery that operates a 2.00-W electric clock for 18 months, we need to calculate:
Energy (E) = Power (P) × Time (t)
First, we convert 18 months into seconds:
18 months × (30 days/month) × (24 hours/day) × (60 minutes/hour) × (60 seconds/minute) = 18 × 30 × 24 × 60 × 60 = 46,656,000 seconds (s)
Then:
E = 2.00 W × 46,656,000 s = 93,312,000 J
However, none of the given options match this calculation. It appears there might be a mistake in either the question or the options provided.
Next, we determine how long a battery with an energy supply of 8.00×104 J can run a pocket calculator that consumes 1.00×10−3 W:
t = E / P
t = 8.00×104 J / 1.00×10−3 W = 8.00×107 s
Thus, the correct answer in part (b) is 8.00×107 seconds.
For the discussion about the ability of solar cells to run different devices, we note that they are suitable for low-energy consuming devices like calculators, but not sufficient to start internal combustion engines in cars and trucks.