1. The problem statement, all variables and given/known data A girl whose weight is 294 N slides down a 6.5 m long playground slide that makes an angle of 20◦ with the horizontal. The coefficient of kinetic friction between the slide and the girl is 0.23. (a) What is the normal force of the slide acting on the girl? (b) How much energy is transferred to thermal energy during her slide? (c) If she starts at the top with a speed of 0.46 m/s, what is her speed at the bottom? 2. Relevant equations N = mgCosQ Ffr = Coefficient of Ke * N Wfr = Ffr * d where.... Ke =0.23 Q =20 degrees m = 294 N g = 9.81m/s^2 d (length) = 6.5m 3. The attempt at a solution (a) N = mgCosQ as I am looking for the normal force. -Sub in values given... N = 294Cos(20) N = 276.27N (b) Ffr = 0.23 * 276.27N Wfr = Ffr *d Wfr = Ffr *6.5 Ffr = 63.54J Wfr = 413.023 Joules (c) I think I have gotten the last two parts right but its the 3rd part that I don't understand. I drew a diagram and because it is a slide (I presume it has a ladder going straight up) which would make it a right angled triangle. 20,70,90 degree angles with a length of 6.5m. Using this I calculated the height to be 2.22m. I know have this formula: Eo = mgh + mv^2 but also V^2 = 2gh I'm given an initial speed but am confused how it relates to anything I have. Am I approaching this question in a correct manner? Thanks in advance to anyone willing to guide me along and help me understand this.