1. The problem statement, all variables and given/known data A stone is thrown from a height 2.1m with an angle of 45 degrees. It fell to the ground 42 m from the throwing position, measured horizontally. Initial velocity is 19,81 m/s, flight time is 3s what is the maximum height? 2. Relevant equations All 2D kinematics equations. 3. The attempt at a solution I plugged in the variables into the equation y(t), and equated Vfin=0, for the maximum height and obtained the correct result which should be 10m from the starting position and 12,1m from the ground. But when I tried to solve the problem using equation Vfin^2=V0^2+2gΔy I obtain 20m which is not correct. Why is it not correct?