Time period of a heavy spring with an attached mass at the end

AI Thread Summary
The discussion focuses on deriving the time period equation for a spring-mass system while accounting for the spring's mass, specifically avoiding energy analysis methods. The user seeks a derivation method similar to that used for massless springs, emphasizing the need for clarity on assumptions regarding mass distribution along the spring. References suggest that the mass of the spring can be approximated with a factor of m/3, where m is the spring's mass, under the assumption that the spring's mass does not significantly alter its vibrating shape. The conversation highlights the challenge of finding suitable resources that meet the user's level of understanding. Overall, the thread underscores the complexity of including spring mass in dynamic equations without relying on energy methods.
thephysicist
Messages
9
Reaction score
0
I want to know the way to derive the time period equation of a spring mass system accounting for the mass of the spring but not using the energy analysis method but by proceeding in the same way as we do by ignoring the mass of the spring. Please help. I did not find any texts at my level. Any links would suffice gratefully.
 
Physics news on Phys.org
What assumptions are you making about the distribution of mass along the length of the spring?
 
Uniformly distributed.
 
thephysicist said:
I want to know the way to derive the time period equation of a spring mass system accounting for the mass of the spring but not using the energy analysis method but by proceeding in the same way as we do by ignoring the mass of the spring. Please help. I did not find any texts at my level. Any links would suffice gratefully.

I did a Google search on "mass on heavy spring" and found loads of hits. I am not sure what your level is but how does this link suit you (it was top of my list)?
 
Thanks for the link but this derivation also uses energy analysis. I want to find an approach that is similar to deriving the equation of motion of a massless spring with an attached mass.
 
The equations of motion for the spring without an extra mass on the end are basically the same derivation as the wave equations for longitudinal waves (not transverse waves in a string under tension).

The mass on the end just changes the boundary conditions at the end.

You will find plenty of references to an approximate solution that includes m/3, where m is the mass of the spring. The approximations is to assumes the spring mass is small enough not to affect the vibrating shape of the spring. That seems to be what sophiecentaur's reference is doing, but it just states the m/3 factor without attempting to justify it.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top