Well because mass flow rate is a product of density and velocity, if one is constant, the other would encounter all the change. So basically I made the "assumption" to hold velocity constant and calculate completely using density. If it wasn't right I wouldn't have gotten the right answer. I'm...
We just got our fluid mechanics quizzes back today and I was unpleasantly surprised with a 13/20 when I was expecting close to a perfect score.
I was counted off a full 6 points (30%) for essentially using the wrong variable because in my rushed state I didn't read the problem carefully...
it would move to the left... meaning it would stretch more, and the weight would move up. the energy would have to come from somewhere for this to not violate thermo law 1.
and I did the math for the ratio traveled, it comes out to like 2:3.
Homework Statement
A cylinder weighing 30lbs is initially at rest on a horizontal surface. There is a spring attached directly below the center, 2ft away from the center point o, pulling to the right horizontally. There is a string attached to the center and to a mass (around a pulley...