Question

For each of the following problems, write up your solutions using the 4-step problem-solving procedure (get started, plan, execute, evaluate) that is detailed in the problem set rubric. Please include sketches of the problem and words describing the steps, not just the math.

3. Rechargeable batteries in laptop computers are both heavy and expensive. Moreover, they can only be charged for a few hundred cycles at best. Because of this, capacitors have been considered as a possible alternative. Let’s say your ultra-low-power laptop requires 8 V to run. You’d like to use it for a minimum of 4 hours using an average power of 1 W. Assume it’s possible to “tap” a constant 8 volts from a capacitor that has a potential difference greater than or equal to 8 V, but cannot exceed 48 V. In order to use this capacitor in your laptop, what would its capacitance have to be? If this were a parallel plate capacitor, how large would the plate area have to be if the plates were separated by a Mylar layer of 0.05 mm thick? Does this seem feasible?

Answer 1