Will object go more high in a projectile motion or in a straight line motion when having same initail velocity?
The object will go more high when it is thrown in a straight line since the angle becomes 90°.
Hence in the formula
[v^2 sin^2(theta)]/2g.
sin(theta) is maximum at 90°
So the maximum height can be attained when thrown in a straight line even with the same initial velocity