Which of the following devices is used to determine the relative density of an acid?

A block of wood of density 0.6 gcm\(^{-3}\), weighing 3.06N in air, floats freely in a liquid of density 0.9 gcm\(^{-3}\). Calculate volume of the portion immersed (g = 10ms\(^{-2}\))

A metal ball of weight W falls through a column of glycerine of viscosity V. If the ball experiences an upthrust U and terminal velocity is attained, then