Body Definition and 1000 Threads

I am asking this question because I found it in a lecture by Stephen Wolfram which you can see at this link at about 54:10: Apparently the question cannot be answered with current methods of physics- Wolfram describes it as "undecidable". But what is the question? When he says "escape" does...

I am a writer, and this is the opening scene in a story I'm currently working on. A girl weighing 110 lbs gets sucked across a room, about 50 yards, then hits the wall. Her boyfriend knows that if he doesn't get her into a stasis pod within 10 minutes, she'll be dead from the massive internal...

There are serotonin imitators, acetylcholine imitators, also several metals, like lead, are very good 'actors' in our body, but is it true that there are also vitamin imitators and hormone imitators in our body?

If a car is on top of a mountain moving with an initial velocity, will it only forces acting on it be the normal force counteracted by the force due to gravity?

I thought this would be an easy lookup. However, after farming several sources, I couldn't find a discussion on it.. Anyway, my question is is this, does a shorter wavelength/higher energy photon bend more around a massive body than a lower energy photon? For instance, if we had two photons...

Homework Statement According to my book, the Golgi body is the organelle of an animal cell which is responsible for *protein modification* and *sub-cellular localization*. I'm trying to fully grasp what is said above (in a manner that is as easy to understand as possible, without involving...

I am absolutely clueless when it comes to drawing free body diagrams. I think I understand the concepts but as soon as I see an unfamiliar system I have no idea what goes where. Are there any resourcess that provide a large number of practice problems (with solutions) for drawing free body...

Is there a way of telling whether the orbit of a body around another, or rather of both around their centre of mass, will give the object in question a circular, elliptical, hyperbolic or parabolic orbit? Thank you!

hi i am araz a mechanic master engineer and i am looking for any article or information about" Instantaneous Center of Zero Acceleration of Rigid Body" because i couldn't find any but "Instantaneous Center of Zero velocity":confused: i hope here i can find some help?!

consider a body revolving around a star and having a velocity v when closest to the star ( distance r) then the velocity of the body at a point farthest ( distance R) is? 1)by angular momentum conservation :: r × mv = R× mV »V = (r/R).v...

Hi all, I am trying to calculate the correlator between two different creation and annihilation operators on a many body system. The system is composed by two wires (left and right) and an energy level between them $\epsilon_{0}$. So we have the creation and annihilation operators on the wires...

Homework Statement At a construction site, a small crane is raising two boxes of nails on a plank to the roof. One box has already been opened and is half full, while the other box is new. The boxes, including the nails, weigh 10kg and 20kg, respectively, and are both the same size. If the...

Let w = (w1, w2, w3) wrt to the body frame of a rigid body, where the body frame is right-handed orthonormal. I have gathered 2 definitions of w from different sources and I am confused at how they connect to one another. One is that the RB rotates about w through its CoM at rate abs(w), the...

Homework Statement Bicycle with a rider applying weight to on pedal. Draw as free bodies in equilibrium. There are different situations. Homework Equations N/A The Attempt at a Solution So I am working on part a). 1. I believe it is only referring to just the pedal, chain, and the two...

Homework Statement Two equal bodies with temperatures T1 and T2. T1 > T2. The specific heat c does not depend on temperature. What is the maximal work which can be done from this system? I have to get equation for max work which includes c and temperatures. Homework Equations This seems to...

If our body temperature falls below 30 degrees C or so, it stops functioning properly and we die. 30 C seems still a rather warm temperature for normal chemical reactions to be able to occur, and in most environmental conditions inhabited by men it still represents a temperature gradient...

Hi all, I am analysing a 2D D-shaped Neo Hookean model in contact with a Rigid link. The details are in the input file attached. Can someone guide me on how to solve this issue?:headbang: Thanks, Bruce

Homework Statement Rigid body with one spring. Homework Equations Torque equations ( M=I * "alpha") The Attempt at a Solution So I think I can solve this problem but there is only one thing I do not understand. When I am writing my torque equation I would think that the weight of the bar...

I would like to know why the threshold voltage increases for an NMOS transistor when the voltage difference between the source and the body terminals is greater than 0. If, for example, the body terminal is connected to -1V and the source to 0V, holes from the p-substrate are attracted to this...

I read that a non rotating planet like Lubricon VI does not have equator because it does not rotate. So why only rotating planets have equator?

According to the documents I have read, Plank made two changes to Rayleigh-Jeans approach in order to produce an equation that matched the black-body radiation, experimental curves: 1) As a mathematical convenience he assumed that the oscillators in the walls of black-body cavity could only have...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Does body fat percentage(s) include all brain fat percentage(s) and all body fat percentage(s)? (When responding to this post) If the answer is 100% yes etc, what is the lowest body fat...

Could someone explain to me how the kinetic energy of a body moving in a circle is like? I got tempted it stays constant as the speed is constant but that turned out to be false. I am interested in places where the body is at top, side and bottom and so on. So I'd like to also know what the KE...

Homework Statement I'm trying to do a little review of Lagrangian Mechanics through studying the two-body problem for a radial force. I have the Lagrangian of the system L=\frac{1}{2}m_1\dot{\vec{r_1}}^{2}+\frac{1}{2}m_2\dot{\vec{r_2}}^{2}-V(|{\vec{r_1}-\vec{r_2}}|) . Now I'm trying to find...

I know it follows a geodesic in space-time, but is it not being able to bend space-time itself, part of the definition? When I google i just find 'follows a geodesic in space-time'. I thought that it also should not bend space-time itself - but this isn't included in the definitions I've...

1. Relevant information This is a two-block-system on top of each other to the right side of a wall, both attached with springs that are also attached to the wall. A force is applied on the bottom block to the right direction, frictions occurred on both bottoms of the two blocks. Here is the...

I understand photon absorption/emission by electrons in atoms, that transition them between energy levels, producing sharp spectral lines. However, I am having difficulty understanding photon absorption/emission by the vibrational and rotational modes of molecules, with respect to black body...

Homework Statement In a uniform gravitational field, there is a uniform solid disk of of mass M and radius R. A point mass m is glued to the disk at a point that is at a distance a from the center of the disk. The disk rolls without slipping. Find the frequency of small oscillations about the...

Homework Statement A body is dropped from a height ##h## with an initial speed 0, reaches the ground with a velocity of 3 km/h. Another body of the same mass was dropped from the same height ##h## with an initial speed 4 km/h. The second body will reach the ground with what velocity ? Homework...

Homework Statement Determine the behavior of a drug in the bloodstream that enters the brain and the amount of this drug in the bloodstream that is delivered to the body at a given time as it decays. The amount of drug in the body is eliminated as described by an exponential decay half life...

So I'm upgrading my Physics Engine's Collision response system (don't worry, this is a pure physics question, no programming involved! Also don't worry about the time of collision, my collision detection system is separate and returns a time of collision for the response system to work with) and...

Homework Statement For the maximum angle for which you have data draw a free body diagram and explain how the forces add to give the resultant (net) force and show the calculations required to determine the acceleration. The lab was about using Galileo's inclined plane to measure acceleration...

Greetings. Well I do not have enough time to pose all of my questions and ideas I can get this thread started off. So let's get right into it. The teeth of a Beaver incorporate a comparatively high percentage of iron in their construction, making them very strong and orange hued. (Also made to...

Homework Statement Can i say a body has heat energy, like it kinetic or height energy? The next formula only shows the energy transfer in change of temperature Homework Equations Heat energy: ##E=c\cdot m\cdot\Delta t## The Attempt at a Solution I guess not, although it's obvious that the...

In the figure A has mass 4 kg. B and C are identical uniform discs, each of mass 2 kg. The string supporting A is ideal. Obtain the acceleration of A I have just one question, Why is pulley C undergoing translational motion ?, it should be rotational motion because it rotates about a fixed axis

Problem: I am having a bit of problem with the signs on the force balance with the constraining force. The system is: Attempt: I drew the FBD with the constraining force for the lumped mass: Then I tried to solve for the constraint force in terms of the spring and damper: For the...

hello! this is a question that iv been working on and can't seem to figure it out, i checked out the other two threads on this same question but they were of no help, anyway here it is: A wedge with mass M rests on a frictionless horizontal table top. A block with mass m is placed on the wedge...

Hi all! I would be interested in paints that show very high absorptivity/emissivity and that can withstand high temperatures (ideally above 1000°C) and used in vacuum. Do you have any commercial suggestions? Thank you!

Why does time dilation occur due to the velocity of a moving body, according to SR?

So, I've had several people insist that a dark colored object will radiate heat faster than an identical light colored body. I do not believe this is the case. We know that dark bodies ABSORB more short wave than light colors, and thus become hotter as a result...but that's not the issue...

Hi I have a problem in understanding the attached free body diagram problem. I have a shaft that is pivoted at the top. Below the pivot is a magnetic bearing with a radial stiffness of 2600N/mm. I've modeled this as a springs in parallel. Below the bearing is a motor with a radial stiffness of...

Inspired by the movie Interstellar which featured a planet orbiting a rotating supermassive black hole with an extremely high time dilation factor (slowed by a factor of 60,000 relative to observers far from the black hole), I was wondering if anyone knows of an equation for time dilation of...

If I know the temperatures of the two thermal reservoirs (one hot, one cold), the area of contact between each reservoir and the body, and the coefficients of conduction, it seems like I should be able to calculate the equilibrium temperature of the body, but I can't seem to figure out how.

So I am designing an apparatus to lift a 500g load up 500mm and I am trying to find reactions. I have filled in these values in my head with my own logic but I don't know how to do the maths and if I am right or not. I can do the initial position ok but it is the final position I am unsure of...

Suppose the box (stone, bullet..., $$m =1$$) is not moving upward because of a lift, but has been shot and has $$v = 20m/s$$ and $$KE = 200 J$$ Gravity is doing negative work and subtracting energy: $$F = -ma = 10 \cdot 1 = -10 N$$ We cannot use the palallelogram here as KE is not a force, how...

EDIT: "In what fashion are atoms or molecules added to a body, then attached, how exactly do they get replaced?" http://imgur.com/pmR8RB9 (I realize atoms are much smaller) Sorry for the crudity of my drawing but I think you get the general idea. I can't picture what happens? I believe they...

Homework Statement An m1 = 7.6 kg block and an m2 = 10.7 kg block, connected by a rope that passes over a frictionless peg, slide on frictionless incline. Find acceleration of boxes and tension of the rope. Homework Equations F=ma I'm not sure what else The Attempt at a Solution I'm really...

Homework Statement Not a homework or coursework question, but given the simplicity of the problem I feel that this is an appropriate subforum. Consider a person spinning a rock on a string above their head at a constant angular velocity, walking away from the observer at a constant linear...

Homework Statement The power delivered in narrow spectrum range near 10 µm from black body source with temperature 1000 K is 10 µW. Not Solved a) What power would be delivered in narrow spectrum range near 1 µm? Solved b) At what wavelength the power delivered takes its maximum? c) Find this...

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