1. The problem statement, all variables and given/known data So I have a ball rolling down a ramp structure from rest and up a curve,to launch out at 15 degrees. The ball lands 100cm away in a hole 0.05cm deep. The height in which it comes out of the ramp is 0.05cm high angle at which ball launches out = 15 degrees above horiontal dx=100cm dy=-0.05+-0.05= -0.1cm *also the lowest point of the ramp is on the ground find the height in which the ball needs to be rolled down the ramp in order to land 100cm away and into a hole 0.05cm deep. 2. Relevant equations Conservation of energy projectile motion equations 3. The attempt at a solution Use conservation of energy equation to find velocity and than input that into dy=vyit+1/2ayt^2 Ei=Ef Ei=KEt+KEr mgh=1/2mv^2+1/2Iw^2 I=2/5mr^2 w=v/r mgh=7/10mv^2 solve for v, v=sqrt(10/7gh)---= launching velocity Use formula dy=vyit+1/2ayt^2 t=dx/vx vx=cos(15)vi vyi=sin(15)vi -0.1=sin15vi(100/cos15vi)+1/2(-9.81)(1/(cos15)(vi))^2 vi cancels vi=launching velocity = sqrt(10/7gh) -0.1=sin15(100/cos15)+1/2(-9.81)(100^2/(cos15)^2(10/7(9.81)h) 9.81 cancels -0.1=sin15(100/cos15)+1/2(-1)(100^2/(cos15)^2(10/7h) solve for h h=-70.9cm Umm, I don't get why my height becomes negative..so I think I did something wrong but I don't know where. ---This is actually from my lab and not a problem so I might be missing something.