This problem was given to me on a test today. I tried my best to figure it out but I'm still not sure, I did find a solution, I am just not sure if the solution is correct. 1. The problem statement, all variables and given/known data A long jumper jumps with an angle of 23 degrees and lands 8.59m away from the jump spot. What is the magnitude of the initial velocity of the jumper? Assumptions: The feet land in the same place as the body (the body is to be treated as an object) Horizontal motion is constant Given: (small "v" is speed, large "v" is velocity) x - components a = 0 Vi = vcos23 d = 8.59m t = ? y - components a = 9.81m/s/s Vi = vsin23 d = ? (assumed zero at landing) t = ? 2. Relevant equations t = d/v at = vf - vi d = vi + 1/2at2 3. The attempt at a solution t = 8.59m / vcos23 from this point, I forgot explicitly the steps I took, but I subbed in what I knew for the initial velocities in an attempt to solve them. I ended up with: -0.3907v2 -0.3907v + 91.2 = 0 I had included units in all my procedures, and the only units left in the equation were attached to the 91.2 and became m2s-2 (metres squared per seconds squared). I went on and used the quadratic formula anyway, despite the unit anomaly and came up with 14 m/s (rounded). I am not sure if this is even remotely correct, and if I am not even on the right track, could anyone show me how to properly solve it? It seems I'm lacking a bit in the math department, though I am at the top of my physics class (top three anyway).