Respuesta :
Answer:
4 seconds
Step-by-step explanation:
To hit the ground, the height here would be zero
Hence We equate the h here to zero.
This means 0 = -16t^2 + 256
16t^2 = 256
t^2 = 256/16
t*2 = 16
t = 4s
The rock will hit the ground after
Answer: it will take 4 seconds after the rock is dropped to hit the ground.
Step-by-step explanation:
The equation representing the height of the rock, h dropped off a cliff after it has fallen for t seconds is
h= -16t^2 +256
By the time the rock hits the ground, its height above the ground would be zero. Thus, h = 0. Therefore
0 = -16t^2 +256
16t^2 = 256
t^2 = 256/16 = 16
Taking square root of both sides of the equation, it becomes
t = √16 = 4
