Question

I don't know how to do this. Working on #2

Answer 1

-- You know how much work the bow does on the arrow.

         Work = (force) x (distance) =  (65 N) x (0.9 m)

-- THAT's the energy the arrow got from the bow, so
THAT's the kinetic energy the arrow has as it leaves the bow.

       KE = (1/2) (m) (speed)²

       so     (1/2) (0.075 kg) (speed)²  =  (65 N) x (0.9 m)

The speed is the only thing left unknown in this mess.
I'm sure you can handle it from here, and find the speed.