I'm stuck. The problem is here: http://wps.prenhall.com/esm_wilson_physics_5/0,7194,229574-,00.html [Broken] Under Physlet problems, #12. Every time I think I find a way to do this, the answer isn't correct. It lets you check the answer, but I can't seem to find a way to go about it. Any help would be good. Thanks!