Body Definition and 1000 Threads

Hi, I have some soft body equations that require first order elasticity constants. Just trying to figure out the proper indexing. From Finite Elements of Nonlinear Continua by J.T. Oden, the elastic constants I am trying to obtain are the first order, circled below: My particular constitutive...

Considering an atom within a rigid body, does the angular momentum of an electron within the atom vary when the body is put in motion? My intuition is that, whether considered in a classical sense or quantum sense, the speed of a given electron in its motion within an atom will be constant and...

I was in doubt if this is the right chapter to place this thread, but it seems there are many talents just here. "we were observing from a decent distance through optics. The weather was frosty, clear, calm. When хххххх appeared from under the arch of the house (he was хххххххх to walk to the...

I'm trying to understand Newton's third law in the context of collisions. Assume that one body has mass M kg and is traveling in the positive x direction with acceleration A m/s^2. Assume that the second body has mass m kg and is traveling in the negative x direction with acceleration a m/s^2...

It's a well known fact that acceleration due to gravity is independent of the mass of the accelerating body, and only depends on the mass of the body it is accelerating towards and the distance from it. One can prove this mathematically very easily. F=GMm/r^2 (equation 1) but also F=ma...

So, to obtain the motion equations I initially plotted the free-body diagram (see picture). Then I’ve tried to get equations, but I’m not sure, do I have done it rightl. I will be gratefull if someone could help me.

Why should the polhode and herpolhode be only circles for axisymmetric body?

Let's say you are riding a bike very fast, and then you sharply turn into a slide (where the bike is sliding perfectly sideways). I'm trying to calculate the angle that the bike would be leaning at, but I'm having trouble creating the free body diagram. Right now I have the normal force and...

I have questions about Black body radiation. see the attached image 1). It explains that the Spectral radiance measurement of 7000K temperature is the same as both 300 and 520 nm wavelength light. See here both A and B shows 60. Is my understanding correct? 2). Is spectral radiance the number...

Sorry if the question is dumb. Please be kind to help

So I’m a high school physics teacher and I came up with the question above. However I haven’t given it to my students because I’m not sure what the answer would be. There is a force holding the gum up, and that force must balance the force of gravity. I’d probably call that an applied force, so...

Can I please ask for help regarding the following: A uniform rod AB of length 3L is freely hinged to level ground at A. The rod rests inclined at and angle of 30 degrees to the ground resting against a uniform solid cube of edge L. Contact between the rod and the cube is smooth and contact...

(Goldstein 3rd edition pg 72) After reducing two body problem to one body problem >We now restrict ourselves to conservative central forces, where the potential is ##V(r)## function of ##r## only, so that the force is always along ##\mathbf{r}##. By the results of the preceding section, I've...

I have a question regarding a homework exercise. My professor asked me to find the radial force in the free body diagram in the image included. There is a weight Fz from above and it is assumed that it is countered by the vertical component of both the Ff (friction force) and the Fn (normal...

I have a body moved by a crane hook and I want to represent the forces that act on the body in the case of translation, rotation and roto translation. Can someone help me? Thank you [Moderator's note: moved from a technical forum.]

Any book on many body Newtonian dynamics?

In the following page (which, despite examining a question that comes up in science fiction, raises valid scientific questions): http://pages.erau.edu/~andrewsa/sci_fi_projects_spring_2015/Project_1/Eilts_Mitchell/Enders%20Game%20Eilts/Enders%20Game%20Eilts/index_Eilts.html I encountered the...

Even if how careful we are, I think it is hard for us to avoid TRACE amount of unknown chemicals that get into our body unconsciously, through different pathway, our mouth, our nose and our eyes or our wound. Could our body handle these foreign chemicals in trace amount and keep us healthy? Does...

Hello All What would be the motion of a weight dropped into a hole drilled all the way through an Earth-sized planet? Would the weight accelerate all the way to the centre and then decelerate until it got to the far side, and repeat this motion forever? OR Would it accelerate initially and...

Air displacement plethysmography I saw a tv programme many years ago which shows this method of measuring the volume of a patient's body. Air displacement plethysmography was a procedure that I saw being used and, tbh, I never asked myself how it works, until now. It's smart, imo. You put...

My reasoning: Gradient of graph = v/s = t t increasing therefore gradient increasing So graph B The answer is C.

I assumed the angular velocity of the center of mass of the two discs about z axis to be w1 note that angular velocity of center of mass of both discs and center of anyone disc about z axis is same, you can verify that if you want, me after verifying it will use it to decrease the length of the...

I have this moment of inertia problem and is a little confused on the semicircle part and if the rest is really right? I get over 10 if I calculate it in crew CAD but by hand I get 7,568032142. What is right and what am I doing wrong?

I solved it by two methods: ----------------------------------------------------- First, by conservation of linear momentum, using the vector velocities of each particle: In the imminence of the impact, the velocity of all the three particles are the same, \vec v_0 = - \sqrt{2gh} \hat j...

Hi I am currently taking a physics course and studying black body radiation.I have already seen a good number of books , but I have a lot of unanswered questions. -What does the black body radiation, which is approximately the radiation of the sun, has to do with standing waves inside a cavity...

Hi, I was recently reading through Systems Kinetic Modeling notes and am struggling to understand the concepts of total volume of distribution and total body clearance. As far as I understand, the total volume of distribution ## V_c ## is the "volume of the compartment into which the...

ma = mg * sinα - fmg * cosα a = g (sinα-f * cosα) v = g*t(sinα - f * cosα) 14.7 = 10 * 2 (sin60 - f * cos60) f = 0.26 Can someone please check if my solution is correct? I'd really appreciate that.

hi guys, I'm trying to write a program in MATLAB to solve and plot equation of motion of 2 body problem but it errors as i don't know what it says! do you know how to help me? please! The main equation is r(double dot)=-(mu)*r(hat)/r^3 The code that i wrote is: clear all close all clc...

Today I read a book in mechanics and encountered a funny proposition about rigid body with fixed point. Perhaps somebody will be interested to propose it to students as a task. This proposition is almost correct:) Consider a rigid body with a fixed point ##O##. Let ##Oxyz## be a coordinate...

Hi. So I was asked the following question whose picture is attached below along with my attempt at the solution. Now my doubt is, since the question refers to the whole system comprising of these thin rigid body 'mini systems', should the Principle moments of Inertia about the respective axes...

The answer says t = Vb - Va/g. Shouldn't it be Va + V(from highest point to point b)/g ?

Yes, heat can flow into a body without increasing the mean kinetic energy of its molecules. Transferring heat energy to an object will raise its internal energy, this will not necessarily cause an increase in temperture. Specific latent heat is the energy required to change the state of one...

So for this question I understand part A but part B is confusing me, when using point B as the centre of the moment, I get different sign for the mad term. If you take clockwise as positive than 100N force and the force at point G are causing a positive moment and gravity is causing an negative...

For this problem I know how to get the answers but I have a few things I’m not 100% sure about. First how do we know that the rod is experiencing centripetal motion? Second, when using moment about point G how do we know that the angular acceleration is equal to zero? And third the radius is 0.4...

So I’m confused about a few things in the solution. Why is it that speed of the V_h appears on both gear a and b? Is it because both gears are both in contact so they have equal speeds just in opposite direction. Same confusion for V_e being on the top of gear b. So Just because gear e doesn’t...

The solutions used the spend of the wheel and its radius to find the angular velocity. I’m confused because I thought to find angular velocity you use the speed at the points of the radius not the translation speed of the wheel itself. Can someone explain this to me please

NY Times article here. Two species of sea slug (like a snail without a shell) have been shown to be able to amputate their bodies from their heads and then regenerate the body. It is hypothesized that this is done to rid themselves of internal parasites.

I don't understand how this can be solved. The official solution was: F=\sigma*T^4 E=F*4\pi R^2*60*60 This doesn't make sense to me, as it seems to imply that the energy that the black body radiates depends on the radius of the shell. For a very large shell the body will reflect...

What is a boundary and how can boundary interactions be used in echolocation and examining internal body structures?

I am sorry if this is a silly question, we know that- Electric Charge is a characteristic property of a Subatomic particle. And, a body is electrically charged by the transfer of electrons. Then, what does it mean by this the charge on a body is denoted by q.What are we talking here. Are we...

We know that for a non-rigid body, the most stable type of rotation of it is the rotation about the axis with the maximum momentum of inertia and thus the lowest kinetic energy. However, for this question involving a rigid body, the most stable axis is the one with the lowest moment of inertia...

Black body radiation formula contains power and exponential terms. Electric discharge in a gas results in the ion acceleration; the ion distribution comprises power and exponential terms too. Any connection between these two phenomena (i.e. black body and potential) could be established?

Components of gravitational force on M: normal force:M*g*cos(90-α)M*g*sin(α) Downhill force: M*g*sin(90-α)=M*g*cos(α) On m: normal force: m*g*cos(α) Downhill force: m*g*sin(α)

Can we use the electricity from the muscle to power an engine (like a prosthesis)?

According to this scientific report ( https://www.nature.com/articles/s41598-017-17526-4 ) written in 2017 : " The construction of a relativistic thermodynamics theory is still controversial after more than 110 years. To the date there is no agreement on which set of relativistic transformations...

Hello, Just checking that my understanding is correct: the nervous system is formed by the central nervous system (CNS), which comprises the brain and the spinal cord, and by the peripheral nervous system (PNS) which bring signals from and to the CNS from and to the rest of the body. Both CNS...

Hi, Does the brain control the physical growth of a human baby? I think if, for some unfortunate reason, the brain is absent, the growth would still take place normally but more like a vegetable. I don't think if the brain is absent, one can even blink the eye or move a finger. But the...

I was researching what the total electrical resistance of the human body was and got some quite far ranging values. It seems to range from 1, OOO to 1OO,OOO ohms. Some quite elaborate ways of testing it too. Then I thought I'd just get the old multimeter out. I have two and both measured about...

Hi everyone Could someone explain what happens in the body when metabolism speeds up? For example, does it produce more stomach acid? Or does it produce more concentrated stomach acid? Thanks