1. Calculate and compare the electric force between a proton and an electron to the gravitational force between a proton and an electron located 10'12m apart. (answer: Fg~10'43N and Fe~10'4N) 2. Explain how a balloon rubbed on your hair can stick to a wall. 3. Use your understanding of equivalent resistance (from The Physics Classroom 2' ) to complete the following statements (be sure to show your work): 1. Two SQ resistors placed in parallel would provide a resistance that is equivalent to one _____ Q resistor. (answer: 1.5 Ohms) 2. Three 3-0 resistors placed in series would provide a resistance that is equivalent to one _____ -Q resistor. (answer: 9 Ohms) 4. The video at the bottom of 06-4 Solar Power page states that we only need 11.2 million acres of solar panels to power the US ( 47 000, 000 GW - h). Verify or disprove that number using the following information: o The average daily incoming solar radiation (a.k.a. Insolation) in Arizona is about 7 kW'h' o the average efciency of solar panels is about 15%; o and that there are 4047 m2 in each acre. Is the video correct (or at least approximately) or incorrect? Explain. (answer: lget ~40,000 GW h)