Scott Starks, PhD, PE Dept. of Electrical & Computer Engineering UTEP Projectile Motion 1 At time t=0, an artillery shell is launched with a vertical speed of v0 from atop a fortress that is situated atop a mountain of height y0. y0 1 2 y g t v0 t y0 2 Projectile Motion 2 1 2 y g t v0 t y0 2 y is the height (ft) of the projectile above the ground at time t (s) g is the acceleration constant (32 ft/s2) v0 is the muzzle (initial) velocity (ft/s) y0 is the height of the cannon above ground (ft) Note: We are only considering vertical height in this example. Projectile Motion 3 Assume the cannon is located 672 ft above ground level. y0 672 ( ft ) Assume the muzzle velocity is 656 ft/s. v0 656 ( ft / s) Projectile Motion 4 1 2 y g t v0 t y0 2 1 2 y (32) t (656) t 672 2 2 y 16t 656t 672 ( ft ) Projectile Motion 5 t (s) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Table y (ft) 672 1312 1920 2496 3040 3552 4032 4480 4896 5280 5632 5952 6240 6496 6720 6912 7072 7200 7296 7360 7392 7392 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 7360 7296 7200 7072 6912 6720 6496 6240 5952 5632 5280 4896 4480 4032 3552 3040 2496 1920 1312 672 0 y (ft) 8000 7000 6000 5000 4000 3000 2000 1000 t (s) 0 0 10 20 30 40 50 Plot Projectile Motion 6 The vertical speed (v) of the projectile measured in (ft/s) at time (t) is described by the equation v 32t v0 v 32t 656 ( ft / s) Projectile Motion 7 t (s) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 v (ft/s) 656 624 592 560 528 496 464 432 400 368 336 304 272 240 208 176 144 112 80 48 16 -16 Table 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 -48 -80 -112 -144 -176 -208 -240 -272 -304 -336 -368 -400 -432 -464 -496 -528 -560 -592 -624 -656 -688 v (ft/s) 800 600 400 200 t (s) 0 -200 0 10 20 30 40 50 -400 -600 -800 Plot Projectile Motion 8