1. The problem statement, all variables and given/known data Question: Calculate the efficiency of a system that uses a falling mass to move a box along the desk. Given (helps to see picture): Weight of (sliding) box = 164g Weight of (falling) mass = 200g Distance of board (platform) = 88cm Time (avg) = 6s (anything missing? I can get it, just point it out [its a lab]) 2. Relevant equations Efficiency = (energy output/energy input) x 100% 3. The attempt at a solution Ei = mad = (0.2kg)(9.8kg/N)(0.88m) = 1.7J Eo= mgh = (0.164kg)(9.8kg/N)(0.88m) = 1.4J E% = (Eo/Ei) x 100% = (1.4J/1.7J) x 100% = 82% Picture I made: w.w.w.i235.photobucket.com/albums/ee170/ShadowedIMG/Homework.png (cant post links) Any input to anything would be very helpful, and thanks for your time.