Velocity v = velocity vo = velocity original f = force m = mass (of projectile) t = time total(in seconds) v - vo = (f/m)t Distance x = distance xo = position of x @ to (usually 0) t = time total (in seconds) to = starting time (usually 0) g = gravity, acceleration of (9.802 ms2, or 32.16 ft.sec2 vo = velocity original x = xo + (vot) - 1/2(gt2) And we can simplify to below, becuase we assume xo = 0. x = (vot) - 1/2(gt2) And we can simplify to below, becuase we assume vo = 0. Since we assume the projectile starts motion from a standstill. x = 1/2(gt2) Projectile Motion Description - It's ok, I don't understand this either. g = gravity, acceleration of (9.802 ms2, or 32.16 ft.sec2 z = vertical rise of projectile (height) vzo = velocity, original, in the z-axis (height) vxo = velocity, original, in the x-axis (distance) z = (vzo/vxo) - 1/2(g/vxo2)x2 Maximum Altitude Achieved zm = maximum altitude vzo = velocity, original, in the z-axis (height) vxo = velocity, original, in the x-axis (distance) zm = (vzo2)/2g Maximum Distance Achieved xm = maximum distance vzo = velocity, original, in the z-axis (height) vxo = velocity, original, in the x-axis (distance) g = gravity, acceleration of (9.802 ms2, or 32.16 ft.sec2 xm = 2(vzovxo/g) Equation of Trajectory z = height b = frictional force constant (air resistance) g = gravity, acceleration of (9.802 ms2, or 32.16 ft.sec2 m = mass of projectile vzo = velocity, original, in the z-axis (height) vxo = velocity, original, in the x-axis (distance) z = {(mg/bvxo)+(vzoxo)}x-{m2g/b2ln (mvxo/[mvxo-bx])} 