The membrane that surrounds a certain type of living cell has a surface area of 6.4 x 10-9 m2 and a thickness of 1.8 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.2. (a) The potential on the outer surface of the membrane is +79.2 mV greater than that on the inside surface. How much charge resides on the outer surface? (b) If the charge in part (a) is due to K+ ions (charge +e), how many such ions are present on the outer surface?

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics

Choose the most likely outcome of this scenario: jen decided to go bike riding without a helmet. while no one is around during her ride, she is thrown from her bike when her wheel goes into a pothole. she is not injured, but she is terrified to get back on her bike. what happens next? a. her physical health is affected even though she wasn't hurt. b. her mental and emotional health are affected because she is afraid to get back on her bike. c. her social health is affected because she is worried her friends saw the fall. d. her overall health is not affected at all by her fall.