PLEASE WRITE AN EXPLANATION TO EACH ANSWER

A liquid $($with constant density$)$ in a vessel with a free surface remains motionless in the portembial volume force field $f,$ p denotes the pressure field. Mark carrect statements and justify them

the vector field grad$(p)$ is tangential to the free surface vector fields: grad$(p)$ and $f$ are parallel in each point of the vessel the surfaces of constant pressure are always flat on surfaces of constant pressure $p,$ arbitrary potential force $f$ is always constant