Robin Hood is known for stealing from the rich to give to the poor. He finds himself surrounded by some angry noblemen who demand he return their gold chest.

Question

Outnumbered, he takes an arrow from his quiver and fires it straight into the air, scattering the noblemen who are afraid it will hit them on the way down. How much time (in seconds) does he have before the arrow hits the ground?

Details and Assumptions:

The arrow's launch velocity is v=120 m/s.
g=10 m/s²
Assume that Robin Hood shoots the arrow from ground level.

Details and Assumptions:

The arrow's launch velocity is v=120 m/s.
                       g=10 m/s²
    Assume that Robin Hood shoots the arrow from ground level.

bobpursley · Answer

hf=hi+vi*t-1/2 g t^2 hf=hi=0 t(vi-gt/2)=0 t=0 t=2vi/g t= 2*120/50=you do it.

unowen · Answer

Answering my own question: h=120t-1/2(10)t² h=120t-5t² If h=0, then 5t²=120t t=24 ☺☺☺☺