Question

an arrow is shot vertically upward 2 seconds later it is at a height of 42m (this may not be necesarily its highest point)with what velocity was the arrow shot, how long is the arrow in flight altogether

Answer 1

v = Vi - 9.81 t
h = Hi + Vi t - 4.9 t^2
42 = 0 + Vi(2) - 4.9(4)
Vi = 30.8 meters/ second

when it hits ground, v = -30.8 m/s

v = Vi - 9.81 t
-30.8 = 30.8 - 9.81 t
t = 6.28 seconds