Problem 17: A lightning bolt strikes a tree, moving 20.2C20.2C of charge through a potential difference of 1.23 X l OZMV Part (a) What energy, injoules, was dissipated? E = Part (D) What mass of water, in kiloggams, could be raised from 15C 15C to the boiling point and then be converted to steam by this energy? In: Problem 18: The voltage across a membrane forming a cell wall is '6 mV and the membrane is 9.5 rim thick What is the electric field strength in the cell wall, in volts per meter? E : Problem 19: Two parallel conducting plates are separated by .9. 8 cm, and one of them is taken to be at a potential of zero volts. Part (a) What is the electric eld strength between them in Win, if the potential 7.2 cm from the zero volt plate is .135 V? E; = Part (D) What is the voltage between the plates in V? A V: Problem 20: In a model of the hydrogen atom, the electron travels in circular orbits around the proton. What is the electric potential, in volts, due to the proton on an electron in an orbit with radius 5. 63 X 10' 10 r) i m. V Problem 21: An electrostatic paint sprayer has a 0.21 m diameter metal sphere at a potential of 25.0 kV with respect to the ground that repels paint droplets onto a grounded object. Part (a) What charge is on the sphere, in coulombs? Q : Part (D) What charge, in coulombs, must a 0.11 mg drop of paint have in order to arrive at the object with a speed of 10.0 m/s, starting from rest? q = Problem 4: An archaeon has 6.5 X 10!15 protons and a net charge of 9.7pC. Part (a) How many fewer electrons are there than protons? Np - M; = Part (13) If you paired them up, what fraction ofthe protons would have no electrons? (Np - Ne) f M; = Problem 6: Common transparent adhesive tape becomes charged when pulled from a dispenser. If one piece is placed above another, the repulsive force can be great enough to support the top pieoe's weight. Assuming equal point charges as an approximation, calculate the magnitude of each charge, in coulombs, if the electrostatic force is great enough to support the weight of a 0.75 mg_piece of tape held 0.95cm above another. (Np - Ne) H