2
votes
1answer
144 views

What forces are exerted on a clothespin in space?

Let's say a clothespin is modeled as a simple torsion spring as follows. Given: $p_1,\ p_2,\ p_3$: point-like objects of equal mass in 2-D space. All objects float in space, i.e. the center of mass ...
0
votes
1answer
65 views

Balloon Expansion

I would like to do a calculation of an expanding balloon represented by a triangular spring-damper mesh system. Also the behavior of the balloon when it is put in a container, where its shape conform ...
0
votes
1answer
544 views

Relationship between angles [closed]

Question: Find the relationship between angles $\theta$ and $\phi$ using the equations of equilibrium and solve for $\theta$. Express your equation for $\theta$ in terms of $\phi$. ...
1
vote
0answers
54 views

Does the slinky base stay perfectly level during the initial free fall [duplicate]

In this related question: Slinky base does not immediately fall due to gravity It is observed that the base does not fall immediately. Obviously the center of mass is in free fall, and the tension ...
2
votes
1answer
179 views

rate of change of spring potential energy $\frac{dU}{dt}$

Suppose we have a setup like this. In orange are two wooden sticks sort of things, and they are attached to the block of mass $m$(as usual) at a joint which is hinge type something. A similar ...
6
votes
1answer
724 views

Slinky base does not immediately fall due to gravity

Why does the base of this slinky not fall immediately to gravity. My guess is tension in the springs is a force > mass*gravity but even then it is dumbfounding.
3
votes
2answers
4k views

Modeling a two-mass, spring, damper system

I'm trying to model a system with two masses, two springs, two dampers, and one applied force using transfer functions. I'll then be inputting it into Simulink. The system looks like this but there ...
0
votes
1answer
297 views

Hooke's law, springs

A spring AB with constant k is hooked in the end A to the ceiling. At the end B of the undefomed spring is hooked a mass of weight 100N. At $t=0$ the mass is let free with no initial velocity. Not ...
0
votes
1answer
758 views

Mass-Spring Damper system - moving surface

I need help with a physics problem, I don't know much about dampers, how can this be solved? we have $y_0(x)=\mu\sin(\Omega x)$ We arrive at this equation for motion (where we define $b$ and ...
0
votes
2answers
309 views

Calculating restorative force with Hooke's Law [duplicate]

Possible Duplicate: Mass points of a Mass-spring model Say I have a spring like the one in the picture below: The point at the top is fixed to a ceiling. The red coloured arrow is the ...
0
votes
1answer
400 views

Mass points of a Mass-spring model

Let's say I have a mass spring model like the one in the picture below: So, there are 3 parts of the spring joined together in an equilateral triangular manner. Each of the joints has a mass of ...
0
votes
1answer
241 views

Question about finding $k$ in Hooke's Law

My textbook (Advanced Engineering Mathematics by Dennis Zill) offers the following explanation of Hooke's Law: By Hooke's Law, the spring itself exerts a restoring force $F$ opposite to the ...
0
votes
1answer
124 views

Why are there two ways to solve for energy of a spring?

I can find the energy of a spring using $F = -kx$, or by using the formula $e = 1/2mv^2 + 1/2I\omega^2 + mgh + 1/2kx^2$. The first way, I get $mg/k = x$, but the second way, I get $2mg/k = x$. Which ...
1
vote
0answers
158 views

Hooke's Law and the shape of coils

I've learned in school that the force in a coil is $F=kx$, linear on how much the coil is stretched. Two questions: Is it always linear for every shape of a coil? Does it remain linear if we ...
2
votes
1answer
192 views

Does a slinky hanging downward double in length if gravity doubles?

Also would a spring under tension greater than the force of gravity pulling the spring downward shrink in both directions until it has depleted it's stored energy while in free fall?
0
votes
1answer
279 views

Value and direction of the force applied by a rubberband on an object

Is there a model that would allow me to compute the value and the direction of the force F applied to the object in this case: I have to fixed points: $ A = (-l/2,0) $ and $B=(l/2,0)$. A rubberband of ...
5
votes
3answers
365 views

How does the shape (form; not cross-section) of a spring impact performance?

Cylindrical compression springs are everywhere and then some applications choose other forms like rectangular or unique polygonal form. What impact does the form of a compression spring have and how ...
0
votes
0answers
79 views

Springs yet again, this time with a picture. Infinite displacement, makes no sense [duplicate]

Possible Duplicate: How could this damped oscillator ever go to infinity? Or negative infinity for that matter? Consider this ! Where I purposely drew the right arrow bigger than the left ...
2
votes
1answer
154 views

Could someone explain to me why this is sometimes right and sometimes not?

I do not remember when, but a while a ago I was told that for a spring with stiffness $k$ and a mass $m$, the equation $-kx = ma$ never holds. (assume a horizontal spring) So if I was given a problem ...
1
vote
1answer
286 views

Wave equation from hooke law - simple question

In the paragraph http://en.wikipedia.org/wiki/Wave_equation#From_Hooke.27s_law it is said, regarding the u(x) function, that Here u(x) measures the distance from the equilibrium of the mass ...
4
votes
1answer
1k views

Hooke's Law question

I have the following question to answer: a force of160 N stretches a spring 0.050m from its equilibrium position. A. what is the spring constant of the spring? The equation for Hooke's Law in my ...
3
votes
2answers
778 views

Solve spring system

I am not physics in training so if anything is unclear please request clarification. I have a set of objects to be placed on a line, linked with springs of known lengths (L) and stiffnesses (K). I ...
7
votes
2answers
13k views

How much force is in a keystroke? (estimated, of course)?

I'm a software developer, and I need to calculate the estimated amount of force expended typing stored text. Preferrably in some interesting way. (i.e. the force exerted on keys thus far is enough to ...
0
votes
1answer
380 views

if a force is 1 newton metre, what is it at 2 meters?

If I have a force, say 24 kg/cm what would that equate to at 2cm? I would like to know the formulae for calculating this. For example. If a motor can hold an object of 24kg at 1cm from its pivot ...
5
votes
2answers
589 views

Tricky spring on a surface question

I have this relative simple-looking question that I haven't been able to solve for hours now, it's one of those questions that just drive you nuts if you don't know how to do it. This is the scenario: ...
7
votes
4answers
1k views

How far does a trampoline vertically deform based on the mass of the object?

If a baseball is dropped on a trampoline, the point under the object will move a certain distance downward before starting to travel upward again. If a bowling ball is dropped, it will deform further ...