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ironhawk316
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Homework Statement
Question Details:
9. Problem: A stone is thrown verticall upward with a speed of 12.0 m/s from the edge of a cliff 70.0m high. How much later does it reach the bottom of the cliff? What is its speed just before hitting the ground? What total distance did it travel?
time=
speed=
distance=
Homework Equations
y = yo + vot + 1/2 at2
Δy = Vot + 1/2 gt2
v2 = vo2 + 2g Δy
v = vo + gt
The Attempt at a Solution
v = vo + gt
0=12 + (-9.8)t
-12= -9.8t
1.22=t
V2 = Vo2 +2g Δy
02 = (12)2 +2 (-9.8) Δy
02 = 144 + (-19.6) Δy
-144 = -19.6 Δy
7.35=Δy
Δy= Vot + 1/2 gt2
77.35 = o +1/2 (9.8)t2
77.35 = o +4.9 t2
15.79 = t2
3.97 = t
1.22 t + 3.97 t = 5.19 t
distance is 7.35m x 2 + 70m = 84.7 m
V= Vo = at
= -12 + 9.8 (5.2)
= -12 + 50.96
= 38.9 m/s
am I close or totally lost? Help please!