Solve Rotating Mass Tensions: Find Tup and Tlow

  • Thread starter Thread starter Ironmely
  • Start date Start date
  • Tags Tags
    Mass Rotating
Ironmely
Messages
2
Reaction score
0

Homework Statement


A mass m is connected to a vertical axle by two strings of length l each making a 45 degree angle with the axle. Both the axle and mass are rotating with angular velocity w. Gravity is pointed downward. Find the tension in the upper string Tup and the tension in the lower string Tlow.
(clue: if lw^2= sqrt(2)g then Tup=sqrt(2)mg


Homework Equations



Fcp=(mv^2)/r
v=wr

The Attempt at a Solution


when considering the y-axis:
Tup/sqrt(2)= Tlow(sqrt) + mg
when considering the x-axis:
Tup/sqrt(2) + Tlow/sqrt(2)= Fcp
Tup/sqrt(2) + Tlow/sqrt(2)= mlw^2

add the equations and then solve for Tup

I think I'm making a mistake when looking at the x-axis, the tension must come from the centripetal force but I am wondering if I'm stating that correctly. I was also thinking about the x-components of Tup and Tlow adding only to the x-component of Fcp but Fcp should be pointed radially towards the axle and also be perpeniduclar to it so then x-component of Fcp is Fcp...Am I making a wrong assumption somewhere here?
Thank you
 
Physics news on Phys.org
Oh, sorry, I figured it out, r in (mv^2)/r is not l but l/sqrt(2)
 

Thread 'Direction of the magnetic field of an oscillating charge'

Hello everyone, I’m considering a point charge q that oscillates harmonically about the origin along the z-axis, e.g. $$z_{q}(t)= A\sin(wt)$$ In a strongly simplified / quasi-instantaneous approximation I ignore retardation and take the electric field at the position ##r=(x,y,z)## simply to be the “Coulomb field at the charge’s instantaneous position”: $$E(r,t)=\frac{q}{4\pi\varepsilon_{0}}\frac{r-r_{q}(t)}{||r-r_{q}(t)||^{3}}$$ with $$r_{q}(t)=(0,0,z_{q}(t))$$ (I’m aware this isn’t...
View full post »

Thread 'Initial conditions for orbits around a wormhole'

Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
View full post »

Similar threads

What angle does the hanging mass make?
Replies
6
Views
2K
What is the Correct Approach to Solving the Deuteron Transcendental Equation?
Replies
14
Views
2K
Finding Electric field E due to an arc
Replies
5
Views
3K
Two masses connected by spring rotate around one axis
Replies
2
Views
2K
Two masses on a rotating platform
Replies
3
Views
2K
System of two wheels of different sizes with an axle through their centers
2
Replies
67
Views
4K
Cylinder with Displaced Center of Mass Rolling Down Incline
Replies
1
Views
2K
Tension Force Problem (applying Work-Kinetic Energy Theorem)
Replies
16
Views
1K
Calculate a specific boost and rotation
Replies
16
Views
2K
A How Are Rotations on the Bloch Sphere Implemented in Practice?
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top