posted by qwertzuiop on .
Marie shoots an arrow vertically upward at a sandhill crane (she misses the crane, so you PETA members can relax). If the arrow travels to a maximum height of 99.5 meters, calculate how fast it was shot.
And, for how much time was Marie's arrow in the air?
a. Vf^2 = Vo^2 + 2g*d,
Vo^2 = Vf^2 - 2g*d,
Vo^2 = 0 - (-19.6)99.5 = 1950,
Vo = 44.2 m/s.
b. Tr=Tf= (Vf-Vo)/g=(0-44.2)/-9.8=2.26s
= Rise time = Fall time.
Tr + Tf = 2.26 + 2.26 = 4.52 s. = Time in air.