A positive charge of q_{t} = 1.0nC is fixed at x = 0.0 cm * y = 1.2 cm . A negative charge of q. = -1.3 nC is fixed at x = 1.8 cm , y = 0.0 cm . (Hint: nano means 10 ^ - 9 and centi means 10 ^ - 2 Make your signs correct throughout !) a) What are the x and y components of the electric field at the origin due to these two charges? b) What would be the x and y components of the force on a negative charge, q_{3} = - 3.0nc , if it were placed at the origin?

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.