Respuesta :
formula
datos
s = 120m
t = 4s
vi = velocidad inicial
s = distancia
g = gravedad = 9,8m/s^2
s = vi*t +gt^2/2
s = (2vi*t +gt^2)/2
2s = 2vi *t +gt^2
(2s -gt^2) /2t = vi
(2*120m - 9,8m/s^2*4s*4s)/2*4s = vi
(240m - 156,8m) /4s = vi
83,2m/4s = vi
20,8m/s = vi
datos
s = 120m
t = 4s
vi = velocidad inicial
s = distancia
g = gravedad = 9,8m/s^2
s = vi*t +gt^2/2
s = (2vi*t +gt^2)/2
2s = 2vi *t +gt^2
(2s -gt^2) /2t = vi
(2*120m - 9,8m/s^2*4s*4s)/2*4s = vi
(240m - 156,8m) /4s = vi
83,2m/4s = vi
20,8m/s = vi