Input
Output
Evaluation Input Image

A pipe of radius R has a fully developed laminarflow of air at P0, T0 with a velocity profile of V = Vc[1 - (r/R)2], where Vc is the velocity on the center-line and r is the radius, as shown in <image 1>. Find the total mass flow rate and the average velocity, both as functions of Vc and R.



(A) V=Vc3m˙=π2νVcR2\begin{aligned}V&=\frac{V_c}{3}\\\dot{m}&=\frac{\pi}{2\cdot\nu}\cdot V_c\cdot R^2\\\\\end{aligned}


(B) V=Vc2m˙=π2νVcR2\begin{aligned}V&=\frac{V_c}{2}\\\dot{m}&=\frac{\pi}{2\cdot\nu}\cdot V_c\cdot R^2\\\\\end{aligned}


(C) V=Vc2m˙=π2νVcR3\begin{aligned}V&=\frac{V_c}{2}\\\dot{m}&=\frac{\pi}{2\cdot\nu}\cdot V_c\cdot R^3\\\\\end{aligned}


Answer with the option's letter from the given choices directly. No punctuation.


(A)


Expected Answer: B

Difficulty: Hard

Subfield: Thermodynamics

Evaluation

Evaluation ID
3a59c213-8e4d-40c6-ad2a-d7709c675546
Created
February 21, 2024
Raw Output
{
  "id": "gen-KciqeOpNb4j8DJuADhDjynornzrV",
  "model": "google/gemini-pro-vision",
  "choices": [
    {
      "message": {
        "role": "assistant",
        "content": " (A)"
      },
      "finish_reason": "STOP"
    }
  ],
  "object": "chat.completion",
  "created": 1708556815,
  "usage": {
    "prompt_tokens": 2024,
    "completion_tokens": 12,
    "total_tokens": 2036
  }
}