In what direction and at what point does the buoyant force on a body due to a liquid, act?

Define upthrust and state it's S.I. unit.

A body experiences an upthrust F₁ in river water and F₂ in sea water when dipped up to the same level. Which is more F₁ or F₂ ? Give reason.

A body of volume V and density ρ is kept completely immersed in a liquid of density ρ_L . If g is the acceleration due to gravity, write expressions for the following —

(i) The weight of the body,

(ii) The upthrust on the body,

(iii) The apparent weight of the body in liquid,

(iv) The loss in weight of the body.