1. The problem statement, all variables and given/known data The problem: There is an illustration and the question is to find the force F to lift a concrete block gate if the the concrete weighs 160 lb/ft3. The block is 3' in diameter and 1' thick. It is in a tank of fresh water 15 ft down. the specific weight of the fresh water is 62.4 lb/ft3 and specific weight of the sea water on the other side is 64 lb/ft3 Knowns: Specific weight fresh water:62.4 lbs/ft3 Specific weight salt water 64 lb/ft3 concrete: 160 lb/ft3, 3' diameterx1' thick 2. Relevant equations equations I see: wt=fb F=F(water)-F(disc) 3. The attempt at a solution Steps I see so far 1. Find area of the disc 2. calculate the Volume of the disc 3. Calculate weight of disc 4. Sum of forces acting on disc -weight acting down -Calculate force needed to act upward -Does this use Bernoulli's equation?