- #1
decentfellow
- 130
- 1
Homework Statement
A tube of length '##L##' is filled completely with an incompressible liquid of mass '##M##' and closed at both of the ends. The tube is then rotated in a horizontal plane about one of it's ends with a uniform angular velocity '##\omega##'. Then which of the following statements are true:
- The force exerted by liquid at the other end is ##\frac{1}{2}M\omega^2 L##
- Ratio of force at middle point and the end point of the tube will be ##4:1##
- The force between liquid layers linearly increases with the distance along the length of the tube.
- Force is constant.
Homework Equations
##\vec{F}=m\vec{a}##
The Attempt at a Solution
Now let's not bother with the options, what I am puzzled about is how to find the force exerted at a linear element at a distance ##x## from the rotation axis. Wouldn't the scenario be just like that of swirling massive rope. In the case of a whirling rope the tension at any point is given by ##\dfrac{M\omega^2}{2L}(L^2-x^2)##, so in this case also wouldn't it be the same. But, wait I also (just like you) doubt that I am entirely correct because in the case of the rope there was no mass or any other body which applied a force (or needed to be rotated at ##x=L##) on the differential element that we were considering at a distance ##L## from the rotational axis, that's why we could find the integral constant by putting ##F=0## as ##c=\dfrac{M\omega^2}{2L}## in the expression ##F=-\dfrac{M\omega^2x}{2}+c##. So, what point do I need to consider for finding out the integral constant in this situation or is it that the situation is not like that of the rope at all.