The document contains solutions to 4 physics problems:
1) Reducing a system of forces on an angle bracket to a single force and couple.
2) Determining the position for a fourth child on a raft given the weights and positions of 3 other children.
3) Calculating the water level needed for a gate to just begin opening due to buoyant forces.
4) Finding the minimum weight of a hollow steel cone filled with water to prevent it from being lifted by the water pressure.