I am not sure how I am supposed to do these problems and I am going to be tested on them soon can someone please help me. 1) An 83 g arrow is fired from a bow whose string exerts an average force of 95 N on the arrow over a distance of 85 cm. What is the speed of the arrow as it leaves the bow? Do I use KE=.5m(v^2)?. If so how do I use that since I dont know the velocity? 2)An automobile is traveling along a highway at 94 km/h. If it travels instead at 103 km/h, what is the percent increase in the automobile's kinetic energy? I have used KE=.5m(v^2) but I dont understand how I get the percentage! Please I need some major help!