On my book, it says the weight of the object equals the weight of the displaced water. Here is a question: A 70-kg ancient statue lies at the bottom of the sea. Its volume is 3.0*10^4 cm3. How much force is needed to lift it? Now, Ignore how much force is needed, just focus on the buoyant force. My book says:Fb=m(water)*g=p(water)Vg. Why should we use volume to solve the problem if the weight of the statue equals to the weight of the object? so we can just do:Fb=m(water)g=m(statue)g=70*10=700N. However, this answer is different from the "correct" one. So I am confused at the concept of equal weight of the fluid and the object. THanks for help.