Banana Bob: We need to find the speed of an arrow
Weight=27g or 0,027kg
Force=75N
Distance=78cm or 0,780
our answer is 65,828m/s and the book says 147m/s
Which is right which is wrong
Hey Bob!
Assuming the bow has an average force of 75 N over a distance of 0.78 m, the energy transferred is:
force x distance = 75 x 0.78 J
This energy is equal to the kinetic energy that the arrow gains:
(1/2)mv
2 = (1/2) x 0.027 x v
2 So the speed in m/s is:
sqrt(2 * 75 * 0.78 / 0.027)
In other words, the book is wrong and you are right!
+6 
+135 
