In cocos2d, there is a method CCJumpBy for handling the sprite movement in air. We move motion code to Box2D as we want my arrows and characters work in physics environment with gravity.
The following materials mentioned how to jump using impulse.
http://www.iforce2d.net/b2dtut/jumpability
It works but not on projectiles such as
1. An archer to shoot an arrow to specified location and hit the target
2. Characters jump to specified platiform
In the reply posts, iforce2d have mentioned several threads that may help to handle the case
http://www.iforce2d.net/b2dtut/projected-trajectory
http://box2d.org/forum/viewtopic.php?f=3&t=7142
http://box2d.org/forum/viewtopic.php?f=3&t=7535