d = Vo*t + 0.5gt^2 = 77,
0 + 4.9t^2 = 77,
t^2 = 15.7,
t = 3.96s. = Time to fall 1st 77m.
d = 0 + 4.9t^2 = 154m,
4.9t^2 = 154,
t^2 = 31.4,
t = 5.6s. = Time to fall to ground.
T = 5.6 - 3.96 = 1.65s. = Time to fall
2nd 77m.
A rock is dropped from a 154-m-high cliff. How long does it take to fall (a) the first 77.0 m and (b) the second 77.0 m?
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