Question
if a ball is thrown downward from a roof top 100meters tall and hits the ground in 3 seconds how hard is it thrown?
Answers
scott
d = 1/2 g t^2 + Vo t ... 100 = 1/2 * 9.8 * 3^2 + 3 Vo
bobpursley
hf=ho+v*t-1/2 g t^2
hf= final position
ho=initial position
v= intial velocity, upward is +
g = -9.8m/s^2
t is time in flight
0=100+v*3+1/2 * -9.8*9
-100=3v-4.9*9
solve for v. I get about -18.6 m/s (negative means downward)
hf= final position
ho=initial position
v= intial velocity, upward is +
g = -9.8m/s^2
t is time in flight
0=100+v*3+1/2 * -9.8*9
-100=3v-4.9*9
solve for v. I get about -18.6 m/s (negative means downward)