Aprojectile is fired with an initial speed of 500m/s and angle of elevation 30 degrees. find the range, max height and speed at impact

Vt =  Voy - at
Vt = initial speed x sin 30 - 10t

0 =  500 sin30 - 10t
0 =  250√3 - 10t
t = 25 √3

hope this helps

Efficiency is an action of doing something. for example when you take a test. good efficiency means you did well but bad effeciency or no effiency means you did bad.