# Does Buoyant Force always act upwards?

I have always used buoyant force as acting upwards in any problem related to fluid mechanics that I have solved. Also, if we push a mug down a bucket of water. It rises up, always, not diagonally even if it is pushed diagonally inside. Does buoyant force always act upwards? If yes, how is it consistent with Newton's Third Law?

• What makes you thinking it may violate the Third Law? May 15, 2016 at 1:13
• Sorry. I meant. If I push a mug diagonally, it comes back in upward direction, Therefore net force is acting upwards whereas my force was acting diagonally. May 15, 2016 at 2:16
• Concerning the Newton's 3rd Law part of the question. I do a demo for the students in my intro classes. I put a beaker partial full of water on a balance and adjust the weights until it balances. Then I suspend a small weight from a wire and lower it the water without letting it touch the glass. What happens is instructive. May 15, 2016 at 3:08
• I see. Carefully observing or perceiving the process, do you find it is more easy to move the mug horizontally than to move it vertically downwards? These are two components (vertical and horizontal) of the reaction force. And it does say (if nature can speak) that the reaction force is vertical, opposite to the buoyant force. May 15, 2016 at 4:37
• Horizontal hydrostatic pressure force cancels out : physics.stackexchange.com/questions/196840/… May 15, 2016 at 6:32