1. The problem statement, all variables and given/known data Your alpine rescue team is using a slingshot to send an emergency medical packet to climbers stranded on a ledge on the side of a mountain. If the height of the ledge is 270m (y = 270m) and the ledge is 390m from the slingshot (x = 390m), what is the initial velocity of the slingshot if the launch angle is 70 degrees? V(o) = ? x = 390m y = 270m Theta = 70 degrees a(y) = -9.81 a(x) = 0 2. Relevant equations Since the only acceleration is constant, I know that I must solve this problem using these equations: V = V(0) + at X = X(0) + V(0)t + 1/2at^2 V^2 = V(0)^2 + 2ax 3. The attempt at a solution When I first attempted the problem, I figured I would have to solve for variables using the y-axis. I used a variation of the third equation: V(y)^2 = V(0)(y) + 2ay And solved for V(0)(y). (V(y) is 0 when it hits the ledge): 0 = V(0)(y) + 2(9.81)(270) I got: 72.78 = V(0)(y) and then I plugged it into: sin(70) = V(0)(y) / V(0) V(0) = V(0)(y) / sin(70) V(0) = 77.45 m/s This was the only valid approach I could think of, but the online HW program I'm using says that this is the incorrect answer. I'm sure that this is very simple and I am just ignorant of something, but can anyone provide any pointers to help me out? Thanks!