physics
posted by Haley on .
An archer puts a 0.26kg arrow to the bowstring. An average force of 200 N is exerted to draw the string back 1.4 m.
(a) Assuming no frictional loss, with what speed does the arrow leave the bow?
m/s
(b) If the arrow is shot straight up, how high does it rise?
m
I got 47 for A
and 113 for B, but neither work?

Work is
W =F•x =200•1.4 =280 J,
W =KE = m•v²/2,
v =sqrt(2•W/m) = sqrt(2•280/0.26) =46.4 m/s.
KE =PE = m•g•h
h = KE/m•g = 280/0.26•9.8 ≈110 m. 
both of these answers
a 280J
and
b46.4m/s
are wrong? 
These answers (v=46.4 m/s, h= 109.89≈110 m) are correct.