Start Learning Free

Before You Begin

Question #42244

Difficulty: 8/10 | 🟢 Free

The Question

A rigid pipe of length L=5 mL = 5 \text{ m} is fixed such that it slopes upward and to the right at an angle θ=37∘\theta = 37^\circ to the horizontal. The entire setup accelerates horizontally to the right with a constant acceleration a=5 m/s2a = 5 \text{ m/s}^2. An ideal incompressible fluid of density ρ=1000 kg/m3\rho = 1000 \text{ kg/m}^3 flows steadily up the pipe. At the lower end (point 1), the cross-sectional area is A1=20 cm2A_1 = 20 \text{ cm}^2 and the fluid velocity relative to the pipe is v1=2 m/sv_1 = 2 \text{ m/s}. At the upper end (point 2), the cross-sectional area is A2=10 cm2A_2 = 10 \text{ cm}^2. Assuming the flow is steady in the accelerating frame, what is the pressure difference P1−P2P_1 - P_2 between the lower and upper ends? (Take g=10 m/s2g = 10 \text{ m/s}^2, sin⁡37∘=3/5\sin 37^\circ = 3/5)

Options

  • A.

    56 kPa56 \text{ kPa}

  • B.

    36 kPa36 \text{ kPa}

  • C.

    16 kPa16 \text{ kPa}

  • D.

    50 kPa50 \text{ kPa}

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Intuition_Breaker

Train your brain to resist "obvious" answers that are designed to deceive your intuition.

Concepts Behind This Question

Equation of Continuity|Non-Uniform Acceleration Constraint|Pseudo Force Directionality

Why This Question Is Tricky

Common Mistakes

This question tests the application of Bernoulli's principle in a non-inertial reference frame, combined with the equation of continuity.

A common trap is ignoring the pseudo-force or incorrectly assigning its direction, which leads students to either omit the horizontal potential energy term (axax) or subtract it from the gravitational potential energy.

Furthermore, students must recognize that the effective gravity vector g⃗eff=g⃗−a⃗\vec{g}_{eff} = \vec{g} - \vec{a} creates a modified potential field Ueff=ax+gyU_{eff} = ax + gy, requiring integration of the pressure gradient along the pipe's specific slope.

Forgetting the kinetic energy term due to the changing cross-section is another frequent oversight.

Quick Facts About This Question

Question Information

SubjectPhysics
ChapterMechanical Properties of Fluids - Class 11 Part 2
ConceptEquation of Continuity
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree