1. The problem statement, all variables and given/known data A 259 g textbook slides up a 22.1° incline that is 2.55 m long. Using conservation of energy and assuming the incline is frictionless, what minimum initial speed is needed to accomplish this? mass = 0.259 kg Θ = 22.1° length of incline = 2.55 m 2. Relevant equations KE = (1/2)*mv2 PE = mgh 3. The attempt at a solution I solved for height of the incline/ramp using trigonometry where the height is opposite to the angle and the length of the ramp is the hypotenuse: h = 2.55*sin(21.5°) = 0.934 Since the incline is frictionless the kinetic energy at the beginning is equal to the potential energy of when the textbook reaches the top of the ramp: KE = PE (1/2)*mv2 = mgh Isolating for the velocity, the masses cancel out v = √2gh v = √(2*9.8*0.934) = 4.27 m/s So I got 4.27 m/s as initial velocity but it doesn't match with any of the answers which are either 4.34 m/s, 7.07 m/s, 3.07 m/s or 6.80 m/s. So I was wondering what I did wrong. Was the velocity I was solving for not initial velocity or was the approach completely wrong? or Did I just make some miscalculations that made it not equal to the first answer?