"given data:"given data: "initial velocity :"v_i=26 m/sinitial velocity :vi=26ms "angle :"alpha=(2pi)/3angle :α=2π3 sin(2pi)/3=0,866sin(2π)3=0,866 "elapsed time to reach its maximum height :"t_m=(v_i*sin alpha)/gelapsed time to reach its maximum height :tm=vi⋅sinαg g=9,81 m/s^2g=9,81ms2