- #1
Resmo112
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Homework Statement
30. A stone is thrown horizontally from a 100 m high cliff with an initial speed of 10.0 m/s. How long does it take to hit the ground?*
A.* 14.5 s
B.* 4.52 s
C.* 10.2 s
D.* 6.27 s
E. 19.2 s
Homework Equations
The 4 kinematics equations
DeltaV=a*t
DeltaX=vi*t+1/2a*T^2
Vf^2-Vi^2=2aDeltaX
DeltaX=1/2(Vf+vi)*t
The Attempt at a Solution
well first I tried to find the final velocity then use the change in velocity to get the time and I got 3.61s but the answer is 4.52 seconds, so I was told that since you're looking at a stone thrown horizontally so you're looking at a vector in 2 dimensions. so I set Vf to Zero where the velocity becomes 0 at the apex and i get 1.02 and obviously that's not the answer either. I'm really kind of stumped on this one and I don't see what else I can do. Any help is greatly appreciated.