Revisica

X1Adapted past paperCurrent specThird5 marks6 min

ENGR271 2025-26 Q1 (data and RD step only)[PARTIAL] Left out: Parts (a)-(d) (absolute and gauge pressure, interface condition, piezometer heights) test Lecture 2 hydrostatics and are in that pack.

An open vertical tank contains a 1.0 m layer of water ( $\rho_w = 1000\ \mathrm{kg\,m^{-3}}$ ) with a 1.0 m layer of oil of relative density $RD_{oil} = 0.8$ floating on top. Take $g = 9.81\ \mathrm{m\,s^{-2}}$ .

(i)
Calculate the density and the specific weight of the oil and of the water.
rho_oil =kg/m^3
gamma_oil =N/m^3
gamma_water =N/m^3
[3]
(ii)
Hence calculate the weight of each layer resting on $1\ \mathrm{m^2}$ of horizontal area.
oil layer per m^2 =N
water layer per m^2 =N
[2]

Formulas it uses

Relative density
$RD = \frac{\rho_{fluid}}{\rho_{water}}$
Specific weight
$\gamma = \frac{m g}{V} = \rho g$

Taught in

ENGR5002 Lecture 1: Introduction