1. **State the problem:** Calculate the mean velocity of olive oil flowing in a horizontal tube of diameter 0.0475 m where the pressure drop per meter is 1000 Pa. The oil viscosity is 80 cP and density is 919 kg/m³. 2. **Convert given data to consistent units:** Viscosity $\mu = 80$ cP = $80 \times 10^{-3}$ Pa·s = 0.08 Pa·s (since 1 cP = 0.001 Pa·s). 3. **Apply the Hagen-Poiseuille equation for laminar flow in a pipe:** The pressure drop per length $\frac{\Delta P}{L} = \frac{32 \mu V}{D^2}$, where $V$ is the mean velocity, $D$ is pipe diameter, $\mu$ is dynamic viscosity. 4. **Rearrange to solve for mean velocity $V$:** $$ V = \frac{D^2}{32 \mu} \times \frac{\Delta P}{L} $$ 5. **Substitute the values:** $$ V = \frac{(0.0475)^2}{32 \times 0.08} \times 1000 $$ Calculate numerator: $$ (0.0475)^2 = 0.00225625 $$ Calculate denominator: $$ 32 \times 0.08 = 2.56 $$ 6. **Calculate velocity:** $$ V = \frac{0.00225625}{2.56} \times 1000 = 0.0008810547 \times 1000 = 0.881 \text{ m/s} $$ **Final answer:** The mean velocity of olive oil in the tube is approximately **0.88 m/s**.