Body Definition and 1000 Threads

all of automate system in our body. digesting food, put oxygen on our blood and pull carbon dioxide out, immune system, wound healing...etc does our brain control all that even without our awareness? or those can still work even without brain order?if true... wow, our brain may inferior to...

Homework Statement In a dark room with ambient temperature T0, a black body is kept at a temperature T. Keeping the temperature of the black body constant (at T), sunrays are allowed to fall on the black body through a hole in the roof of the dark room. Assuming that there is no change in the...

I'm not sure this is the best fourm to post this, but... How much heat, preferably in watts, does perspiration dissipate under mild exertion (i.e. walking) on a 90° F day? Assume the individual is hydrated and not starving. Also assume they weigh 180Lbs. How much heat would have to be...

Hi! I am trying to simulate the rotation of a planet around a star, using the 2nd order Runge-Kutta method (I am starting with this and I will try 4th order later, I am new to this topic). I have this code but it doesn't work. When I plot y(x) I should get a circle, but I don't get it. Any idea...

Homework Statement The context of this problem involves a dolly pulling a trailer, and I am trying to establish the basic free body diagram for the trailer. Is what is done so far acceptable and is this a step in the right direction? Homework EquationsThe Attempt at a Solution I am confident...

Homework Statement Hi everyone. I'm a high school teacher. My background is physics and math, but right now I'm teaching a course that involves some basic (grade 10) biology. I don't know much about bio, so I need your help! Right now, we're studying the organelles. I'm trying to put together...

suppose a platform "P" is rotating about the z-axis wrt x-axis . another platform "Q" rotating about z-axis below "P" with same angular velocity wrt x-axis standing on Q , P is at rest wrt Q, After some time rotational inertia of P about z-axis starts changing with time standing on Q , P will...

How close do objects have to be to be considered a single mass? On Earth, with solid objects, the answer would seem to be intuitive: if an object can't fall any further then it is 'connected' to, or part of Earth's mass. But what about something like a gas giant, or a star? I started thinking...

Suppose we have an equation in inertial frame A. \begin{equation}\frac{{}^Ad\bf{H}_C}{dt} = \bf{M}_C\end{equation} Now we want to switch to body fixed frame B. For this need to employ correction factor {}^A\bf\omega^B\times\bf{H}_B. Why do we have this correction factor? How to derive this...

Homework Statement The speed of a falling body might be based on the observation that the velocity of a falling object seems to increase the further it has fallen. Model the hypothesis "The speed of a falling object is proportional to the distance it has fallen" as a differential equation...

Homework Statement how can the average density of the body equal to the density of fluid(2nd photo) ? the object is not completely submerged in the liquid , so the density of object should be lower , right ? Homework EquationsThe Attempt at a Solution

Recently I came upon the description of medical tests for hormones like cortisole, or tyroid hormones like T3 and T4, which use polyclonal antibodies from hamsters, pigs, sheep or thelike. As far as I know, they are obtained by vacunating these animals and harvesting the antibodies from their...

Homework Statement "When a high-speed passenger train traveling at 161 km/h rounds a bend, the engineer is shocked to see that a locomotive has improperly entered onto the track from a siding and is a distance D = 676 m ahead (Fig.2-29). The locomotive is moving at 29.0 km/h. The engineer of...

Hello. Recently I've been trying to understand this problem but I'm not sure if I'm doing it correctly. So I'd like to show you some statements formed from my understanding on the subject and you guys could correct me if I'm wrong. General: 1)The problem has 3*3=9 degrees of freedom and n...

Supose we have a ¨U-shaped" metal bar, stuck in the ground, and I aply a force on the top of the part on the right, trying to make it wider. If I were to avaliate the forces acting on a specific part of the bar that includes the point that I´m applying the force, let`s say the portion from that...

Homework Statement At time t, the position of a body moving along the s-axis is s= t^3 -12t^2 + 36t m(meters) Find the total distance traveled by the body from t = 0 to t = 3. Homework Equations Derivatives The Attempt at a Solution I got the derivative which is 3t^2 - 24t + 36(meters) I...

I see that black body radiation slowly depletes a body's thermal energy, which is just another way of saying that black body radiation depletes the kinetic energy of a body's constituent particles. But does black body radiation also cut into the kinetic energy of the body as a whole, such that a...

Homework Statement Two boxes, A and B, are connected to each end of a light vertical rope, as shown in the following figure. A constant upward force 74.0 N applied to box A. Starting from rest, box B descends 10.6 m in 3.00 s. The tension in the rope connecting the two boxes is 33.0 N This is...

Homework Statement A ball of mass of 1Kg is held in hand. The moment it is released from hand, without any delay it is hit by an external force of 100N in upwards direction. How high will the body go ? Homework EquationsThe Attempt at a Solution I know how to solve if instead of Force we...

+ A man is holding a closed cage on the palm of his hand with a bird in it. When the bird flies with an upward acceleration inside the cage, it feels heavier. But the force due to the bird in the cage is actually an internal force on the cage, and internal forces don't cause acceleration of...

Homework Statement What will be the speed of sound in a perfectly rigid body? Given : In a hypothetical situation we have a rigid body find the speed of sound when it passes through the material. Elasticity of medium = ∞ Homework Equations velocity = √E/ρ ρ = density E = elasticity of medium...

1. Homework Statement Given the picture, find theta, and the magnitude of the force going from point A to B. I have asked multiple people how to solve this problem and they have no idea, I end up getting 2 equations with 2 unknowns but then when I try to solve for theta I get 70cos(theta) -...

Is the Human body capable of creating any type of frequency ? Of course vocally but beyond that ... . What devices are in existence that can measure or see frequencies of living things ? Have there been experiments with documented results that shows frequencies created by the human body ?

Homework Statement If you have a body that weighs 100 N dipped in oil that has density equal to 0.8 g / cm³. This same body when immersed in water begins to weigh 60 N. How do I find the density / specific body mass? Homework Equations Solution= 1,3 g/cm³ The Attempt at a Solution Already...

If you have a body that weighs 200 N dipped in oil that has density equal to 0.8 g / cm³. This same body when immersed in water begins to weigh 60 N. How do I find the density / specific body mass? Already tried using the formula of the apparent weight = actual weight - buoyant and not worked...

I understand why a black body absorbs every frequency(it is the definition of a black body!) but i do not understand why it also radiates at all frequency spectrum.

Wikipedia writes: "Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment". Why does it write "thermodynamic equilibrium"? If it is not in a thermodynamic equilibrium, then what changes as far as the absorption...

Homework Statement A car attempts to accelerate up a hill at an angle θ to the horizontal. The coefficient of static friction between the tires and the hill is µ > tan θ. What is the maximum acceleration the car can achieve (in the direction upwards along the hill)? Neglect the rotational...

Everywhere I ready about HF or DFT the term exchange correlation functional comes up. I have a couple of fundamental questions about these: 1) Books say that the correlation energy is the difference between the exact energy (lets say we've found that somehow) and the hartree-fock energy and...

So I was thinking, if the body has its own electrical currents... especially in the brain, then the brain must have an electrical field that extends infinitely. If that is the case can the brains electrical field interact with the real world and influence it. So for example if the field was...

I accept the fact that this question has only theoretical significance although any insight into it would provoke a lot of interest. Thus what would the gravitational field strength of a body (say a mass of 1kg) with a velocity greater than the speed of light be and how could any potential value...

The above states that the velocity of point Q relative to P is represented by dr/dt. However, it also states that ∂r/∂t is the apparent velocity of Q in Pxyz. How does that make sense? I mean P is the origin of axes Pxyz so surely the velocity of point Q relative to P should be the same as the...

I have several questions that I am seeking clarification on. The first 2 are rather simple: 1) The formula for r describes the blue streamline (the stagnation streamline) right? (Just confirming) 2) I assume that the stagnation streamline is called so because it passes through the stagnation...

please explain why? Take 2 cases,and explain how is the direction of friction different in these 2 cases. CASE 1:uniform circular motion CASE 2:non uniform circular motion my thought was,friction opposes relative motion,so it must be tangential to the particle at each and every point. i very...

Homework Statement A charged body, moving with a velocity of 8.0 * 104m/s at an angle of 30.0° with respect to a magnetic field of strength 5.6 * 10-5 T, experiences a force of 2.0 * 10-4N. What is the magnitude of the charge? Homework EquationsThe Attempt at a Solution I have no idea where to...

1. The Question Unable to find the work done by spring on the object sliding down the rod as shown below: Homework Equations Work Done by Spring Force : -1/2 * KΔx2 --(1) where k = Spring Constant Δx = Change in Spring Length[/B] 3. Where the problem occurred While seeing the solution...

Homework Statement Draw the free body diagram of the system. (I know that's not what the problem is, but that's what I need clarity on) Homework EquationsThe Attempt at a Solution So I drew the same thing, more or less, but for mine Ay went up. This was how a very similar problem was done -...

Homework Statement Complete a free body diagram for the truss structure with a weight attached to node 2 (this is known as 151N) Homework EquationsThe Attempt at a Solution I have attached my Free Body Diagram The diagram is to display what is know at the start of the problem before working...

Homework Statement How come for the following image when I assume block B slips up, block A does not move. The free body diagram at block B does not have a normal from the ground. This is a static friction problem. [/B]Homework Equations No relevant equations all theory[/B] The Attempt at a...

Homework Statement Component A is pushed vertically down with a known force F into component B. The angled surface of B is parallel to the angled surface of A. The contact between A and B is rough and so is the contact between B and the ground. The coefficients of friction are known and so is...

1. Problem Statement Assume there is an rigid object with mass m in 2D space, an impulse J = FΔt is applied at time t1 at the particle Pimp and Pimp is on the exterior boundary of the object. The impulse cause a free plane motion of the object and the object is only affected by the force of the...

Homework Statement A hemispherical cavity of radius 1.0 m is covered with a plate having an opening of 0.2 m diameter drilled at its centre. The inner surface of the plate is maintained at 700 K by a heater embedded in the surface. Let the inner surface of the plate be 1, the surface of the...

Homework Statement Consider an arbitrary rigid body with an axis of rotational symmetry, which we'll call ## \hat z ## a.) Prove that the axis of symmetry is a principal axis. (b) Prove that any two directions ##\hat x## and ##\hat y ## perpendicular to ##\hat z ## and each other are also...

Humans lost body hair in order to lose heat more efficiently according to this article. http://www.independent.co.uk/news/science/why-humans-lost-their-body-hair-to-stop-their-brains-from-overheating-as-we-evolved-8498623.html So , some humans moved out of Africa and into the cold regions of...

I mean, a body with higher temperature has higher energy so is it heavier than before? We know from e=m*c^2 that energy is equivalent to mass

Sorry if this question has already been addressed. I know that, at least for a point mass or a rigid body traveling at constant velocity, in special relativity kinetic energy T is defined as: T = E - Mc2 where E is the body's total energy and M its invariant mass. I have a problem in...

Homework Statement What is the acceleration of a body which is moving in opposite direction(assuming negative velocity) and is speeding up? Homework Equations acceleration=the rate of which an object changes its velocity The Attempt at a Solution In my opinion, an object moves with a negative...

Hi, I am having some problems conceptualizing the Euler's Theorem. Any help will be greatly appreciated. In Goldstein's book the Euler's theorem is stated as 'Any displacement of a rigid body, whose one point remains fixed throughout, is a rotation about some axis', then he has proven that the...

in the figure a rigid body - a circle- is moving such that its centre is moving in a circular path but the orientation of the body is fixed with respect to the centre of the body (the circle). According to def of rotion of rigid body - Rotation of a rigid body about a fixed axis is defined as...

http://arxiv.org/pdf/1511.01098.pdf We conclude that the “problems” often cited as challenges to ΛCDM are resolved in simulations that reproduce the dynamical constraints of the Local Group environment and include a realistic galaxy formation model. Reionisation and supernova feedback allow...