it}. A roller coaster uses EDD EDD J of energy to get to the top of the rst hill. During this climb= it gains soc J of potential energy and pauses {velocity = U} for a fraction of a second at the very top before heading down the other side. a} Draw a Sankey diagram showing the flow of energy during the roller coaster's climb. b} What's the kinetic energy at the very top? How do you know? c} What would he the \"useful energy" during its climb to the top? How do you know? d} How much energy was \"lost" due to friction {heat} and sound? (Use Elam = Em\"). e} Calculate the efficiency of the roller coaster during this part of the ride {the climb). 11. The roller coaster from the previous question is finally released from its pull up the first climb (where its potential energy is 500 000J) and begins its decent downwards. The roller coaster heads down and levels out as it hits the original level. a) Since they are back at the original level, what do we know about the potential energy at this point? Why? b) If we know that we lost 200 000J to heat energy during this first drop, what is the kinetic energy at the bottom? (Use Ebefore = Eafter) c) What is the efficiency of the roller coaster during this part of the ride? 12. Discuss how improving energy "efficiency" can improve the world. Provide examples