I have a question about buoyancy and Archimedes principle.
    The way it is usually stated is that the buoyant force
    equals the weight of the displaced fluid. I saw the
    following problem:

    An object that weighs 50N displaces a volume of fluid
    weighing 10N. What is the buoyant force?

    I believe the answer would be 10N based on Archimedes
    Principle. The net force acting on the object would be 40N
    but the buoyant force would be 10N. The answer key states
    that 40N is the correct answer.

    Am I wrong on this?

    This is my first year teaching Physical Science and I'm
    afraid I may be rusty. (Previously taught math and Life