Physics:
the amount of resting energy in joules, contained in half a kilogram of potato, s
expression.
2. a) Now, consider that an hour of CFL use consumes 1.4 x 10-2 kWh (kilowatte
kilowatt-hour
If each kilowatt-hour of electric use is equivalent to 3.6 x 10 joules of energy, then
the energy in joules used by the CFL in one hour.
b) If we could use the energy released by half a kilogram of potato, approximately
hours will we be able to light the CFL from that energy?
1. According to Einstein theory, all the matter has energy. The expression 0.53x10
Answers
Step-by-step explanation:
Power is associated by many people with electricity. Knowing that power is the rate of energy use or energy conversion, what is the expression for electric power? Power transmission lines might come to mind. We also think of lightbulbs in terms of their power ratings in watts. Let us compare a 25-W bulb with a 60-W bulb. (See Figure 1(a).) Since both operate on the same voltage, the 60-W bulb must draw more current to have a greater power rating. Thus the 60-W bulb’s resistance must be lower than that of a 25-W bulb. If we increase voltage, we also increase power. For example, when a 25-W bulb that is designed to operate on 120 V is connected to 240 V, it briefly glows very brightly and then burns out. Precisely how are voltage, current, and resistance related to electric power?