physics
posted by yeh on .
I'm very confused.
What is the range of an arrow shot horizontally at 85.3 m/s if it is initially 1.5m above the ground?
I'm guessing 1.5 is delta Y and initial velocity at 85.3 m/s and final velocity at 0 m/s. I just don't understand how I'm supposed to get the answer.

YOu have to break it into vertical and horizonal components.
Use the vertical to find how long it is in the air:
yfinal=yinitial+vyinitial*time+g*time
0=1.5 + O*time9.8*time
time in air=1.5/9.8 seconds
Now the horizontal distance:
xfinal=xinitial + vx*time + a*t
xfinal=0 + 85.5*1.5/9.8 + 0
and you have it. 
This type of questin is sort of a trick question, because the horizontal velocity has no effect on the answer.
It is no different than dropping an object from 1.5m
Just calculate how long it takes an object to fall 1.5m due to gravity, that is your answer.