1. The problem statement, all variables and given/known data Two boxes are connected over a pulley and hel AT REST. Box A has a mass of 15kg and box B has a mass of 12kg. If the bottom of box A is originally 85cm above the floor, with what speed will it contact the floor when the system is released? Use conservation of energy and assume that friction is negligible. (Hint: Think abou the total energy of the system before and after the block A is released) 2. Relevant equations ET= mgh + 1/2mv squared Ek=1/2mv squared Ep=mgh 3. The attempt at a solution Before released: Eta= (15)(9.8)(.85) Eta= 124.95J After released: Etb= mgh Etb= 12(9.8)(.85) up to this point, the test says I have it write (as seen from the teachers marking) then this is where i somehow went wrong: 124.95-99.96= Change in Energy *at this point, the marker said, "B HAS Ek TOO!" then i did: 24.99= Change in Energy 24.99= 1/2mv squared 24.99= 1/2(15)v squared 3.332m/s=v 3.3m/s=v This is unfortunately not the correct answer. If anyone can assist me in where i went wrong that would be great!