Does upthrust ONLY occur in water?

Answer 1

Nope. it occurs in other liquids and even things. like in the air. for example, when you throw a pen in the air, you will find things like... when you throw a pen, there is a push from the muscle and the gravity. The push from the muscle is greater in this occation so the pen goes up. And when it falls, there is nomore of the push from the muscle and there is an upthrust and gravity. (this is where upthrust works) the force of gravity is greater so it falls. Also, it is because of the upthrust that we are standing on the earth. There's an upthrust acting on us as well as the gravity. But ofcourse, as the gravity is stronger, we do not float up to the sky. but if there wasn't any upthrust, we would be sinking into the earth by now! Also upthrust acts on other liquids like oil and salt water.... whoa.. i wrote alot... hope it helped you!