1. The problem statement, all variables and given/known data A 100 lb bag of sand is lifted for 2 seconds at the rate of 4 feet per second . find the work done in lifting the bag if the sand leaks out at the rate of 1.5 lbs per second. 2. Relevant equations 3. The attempt at a solution Here's my attempt at it: work = force x distance force = 100-1.5t distance = 4t work = 400t-6t2 Now I integrate for t=2 and t=0 ∫(400t-6t2)dt =200t2-2t3 for t=2 and t=0 =800-16=784ft-lb Any mistakes?