1. The problem statement, all variables and given/known data A ball is thrown at the angle 30 degrees with an initial speed of 6 m/s, it takes the ball 3 seconds to hit the ground. Calculate the height where the ball was thrown http://img355.imageshack.us/img355/2407/phyuq7.th.jpg [Broken]http://g.imageshack.us/thpix.php [Broken] 2. Relevant equations 3. The attempt at a solution I tried to solve this using the equation: yf = yi + Viy *t - 0.5 * g * t^2 yf-yi = (6 * sin(30) * 3 s) - (0.5*10*3^2) = 9 - 45 = -37 why is it negative? What am I doing wrong here?