Find the differential equations of motion of a projectile in a uniform gravitational field without
For the motion of a projectile,
in horizontal, sx = ux t
in vertical, sy = uy t + 1/2 gt2
KE = 1/2 mv2
PE = mgh
The Attempt at a Solution
L = KE - PE
= 1/2 m ( vx2 + vy2 ) - mgy
Then find their partial differentiation in terms of x, x_dot, y and y_dot.
However, the answer claims that there is z-direction motion.
Why z direction takes into the case?