Body Definition and 1000 Threads

It is said that around 90% of the cells in a human body are symbiotic bacteria living thanks to us. When we die, do most of them also die? Or do they manage to survive without us and find a new 'home human'? And opposite, when and how do we get all those bacteria after conception? Do we get...

Generally pressure in a liquid changes with height at which we measure. But still blood pressure remains almost same throughout the body. How is this possible?

We know that Force= Mass x Acceleration. When the force applied on a body is 0 the accelaration produced in the body is also 0. (F=m a). So, what will be the mass of a body on which no force is applied and no acceleration is produced? [ mentor note: post moved from New Member...

I want to get a half convex lens (thick in the middle, flat on one side). And coat it in thermally and optically reactive transition filters. They are to be segmented so to reduce spread of filtering. This will give a view of the sky with any bright light inhibited at the focus. Next to the...

I want to know, excluding the sun with an appropriate boundary, whether it is possible for the balance of bbr to be positive for outerspace rather than on earth? I am thinking of a half convex with an active polariser across-the outer surface which allows through most radiation below the...

3-D Why in bcc central atoms does not touch other atoms in that layers while in that of hcp and all others cases central atoms touch atoms in that layer..

I know from physics 101 that f = ma. And if I want to lift an object straight up i have to multiply its mass times gravity (acceleration) and I get the force I need to require to overcome it. But what about lifting your body out of bed? Just the part where you physically get up from the lying...

Homework Statement In the picture, I am confused with the sign of the moments. When taking moments about D, the moment due to the 100N is taken as positive, but when they take moments about B, its negative. Homework EquationsThe Attempt at a Solution Shouldn't both cases be negative since in...

Homework Statement A black body absorbs all incident electromagnetic radiation, including visible light which has wavelengths from 380nm to 750nm. IR radiation has wavelengths that are so long they are measured in microns. That suggests that visible light has a higher frequency than IR, and...

Hi. I'm trying to write some anatomical systems for a game I'm coding, and i need some good data to work from. Our game is about dogs, not humans, but i figure a human will be close enough What I'd really like is a case study of a specific organism, and i'd like to know the compositions, by...

Can you explain why the free body diagram of each members are as shown? I kind of understand why the FBD of the member on the left is drawn as shown. But the FBD on the right is confusing, Why does it have a component in Y (upward) direction? thanks!

I tried to find an answer everywhere but didn't found it and I am not strong at physics so please help me I need to know equations for minimum speed required for some body to fly horizontally depending on it's mass , height of fligth and distance to fly . I mean object must travel some...

For example, a 1-m bar fixed to a wall holding a weight of 100 N, like this: How will the free body diagram of the second case different from the first?

I wondered about possibility of using ground effect by blended wing body, turboprop planes. Purposes: -to save fuel (for example for flying tankers); -to return partially damaged plane; -to hide under radar and become visible for ships in the last moment; -to allow flight of overloaded plane...

Homework Statement There was a question in which an object was released upwards from Earth with a velocity of ## 2\sqrt {gR}##. Using conservation of energy I found that the speed of the body in the orbit was ## \sqrt {2gR} ## Everything's fine till now. But then I wanted to find the height at...

Homework Statement 2 masses, m1 and m2 are connected by a cord and placed on a frictionless table as shown in the diagram below. m1 slides on the frictionless table while m2 is hanging from a light frictionless pulley. What would be the mass of the hanging mass m2 if we know that the tension in...

I know that a black body is an idealized body that absorbs all the incident EM radiation. And I also know that the BB emits a spectrum of thermal radiation that depends on its temperature. What I cannot understand is the re-emission. For what I've read, when in thermal equilibrium, a BB absorbs...

I have a question about body inertness. Is moment of inertia is unambiguous inertness characteristic?

How the relative angular momentum of two particles can be detect by detector in two particle decay (center of mass frame)? I am curious about the signatures/differentiation between different relative momenta, means how one can decide that it is L=0, L=1,2,3,...? Of course the distribution would...

Homework Statement Say a human is moving through space with constant acceleration due to gravity. There are no external forces/torques on the body other than the force of gravity. The person applies an internal torque at some joint, let's say the knees, so that they bend. Assume the rest of the...

I would appreciate someone's advice on the following question: "An airplane was moving in the forward direction on the runway when it suddenly stopped. When the airplane stopped, some passengers who did not put on their seat belts fell forward from their seats. Would a passenger of larger...

Homework Statement In our science class, we had to draw a free body diagram of an ice skater. The ice skater pushes against a force plate and that results in her skating in the other direction. (Newton's third law of motion). We have to use Newton's three law of motions to explain this...

Homework Statement I have a body which is instantiated on Earth at some latitude, longitude and altitude. The body has acceleration which is expressed in body coordinates and the acceleration can be integrated to obtain the velocity vector which is also expressed in body coordinates. ECI and...

Hi there, In a two body decay process like ## B \to l \nu ##, there is a factor ##| \bar{l} (1-\gamma_5)\nu|^2 ## in the matrix element amplitude, in which equals ##| \bar{l} (1-\gamma_5)\nu|^2 = (/\!\!\! p_l+m_l) (1-\gamma_5) /\!\!\! p_\nu(1+\gamma_5) = 2(/\!\!\! p_l+m_l) /\!\!\...

http://rt.com/news/248473-transplant-head-body-canavero/ what do you think about this, if it is true can i have one mines knakered

Homework Statement I was working through my text on deriving the tensor for Angular momentum of the sums of elements of a rigid body, I follow it all except for one step. Here is a great page which shows the derivation nicely - http://www.kwon3d.com/theory/moi/iten.html I follow clearly to the...

Hey all, I'm making a physics simulation for training an algorithm of mine, I'm running into issues on the rigid body physics simulation. Let's say I have a leg composed of a calf and a thigh. gravity will be acting on both, and the calf is attached to the thigh, Any suggestions on how I would...

1. A grinding wheel of mass 5 kg and diameter 0.20 m is rotating with an angular speed of 100 rad/s. Calculate its kinetic energy. Through what distance would it have to be dropped in free fall to acquire this kinetic energy? m = 5 kg, r = 0.20/2 m = 0.10 m, g = 10 m/s2, ω = 100 rad/s 2. v =...

Homework Statement A stick of length L and mass m is falling on a table with kinetic friction uK and static friction uS. Find the equation that determines whether the rod will stick or slip. If m = 10kg and L = 100cm, uS = 0.8, uK = 0.7 and initial theta = 30 degrees find the initial accel for...

Homework Statement Consider a person in a room with an air temperature of 21C. The persons core body temperature is 37C and their surface tissue thickness is 5 mm. If the total surface area of their skin is 1.5 m2, and they are wearing clothes of a thickness of 2 mm and the surface heat...

Homework Statement This is a problem I picked for my calculus one class that I would like to solve, then model the solution using the sandbox video game universe sandbox. I would like to calculate the closest stable orbit of the moon, if possible allowing for some eccentricity in the orbit...

Homework Statement I want to sum the forces perpendicular to the pendulum and sum the moments about the pendulums center of gravity. Homework EquationsThe Attempt at a Solution P\sin \theta - mg\cos \theta - N\cos \theta = -m\ddot x\cos \theta + ml\ddot \theta -Pl\sin \theta - Nl\cos \theta +...

hello everybody, I have a question regarding the fictitious force (d'alembert force) we usually add to an examined body in a noninertial reference system. As I understood from reading and leraning about this topic, this force is artificially added only to compensate for exploring this body in...

I'm working on a homework problem for Statics and I'm stuck. Could someone please help?Problem: Draw the internal force (N,V,M) diagrams and include all significant figures Here is all of my work: Resulting F from W1: W(x) = W1 ∴ F2=∫02b W1dx eq (1) ⇒ F2 = W1⋅2b x1 = (F1)-1 ∫02b W1dx =...

Suppose some energy, say light energy transfers from one body to another .. Then will the light energy transferred to the second body also be in the form of light energy? I mean are there any chances that the energy transferred between two different bodies be of same kind of energy? If yes...

My question is, given that the Sun is composed almost entirely of just hydrogen and helium, why is the spectrum from it continuous and not an emission line spectrum? This applies to other stars as well. There are other elements of course present in the Sun, but they are present in very small...

Homework Statement Most physics problems that involve a falling body assume constant acceleration. How does one account for the changing acceleration if a body is dropped from a very high altitude? Homework Equations With constant acceleration, d = (1/2)at^2 or t = sqrt(2d/a) but a is not...

Hi, This is not really a homework problem, but a project I'm working on. So, I am trying to build a Simulink model for my quadcopter. I derived the equations of motion using the Newtown-Euler method in the body frame to get transnational and angular acceleration. For the transnational part, I...

Homework Statement A rectangular box is being pulled by a rope with a force T on a horizontal surface, with a friction coefficient μ. What is the minimum angle α at which it will lift of the surface? See attached image. Homework Equations \begin{equation*} \tau = rF\sin\alpha \end{equation*}...

Homework Statement The problem is this: A car is evenly slowing down from 30 km/h to 0 in the time of 2 seconds. Radius of its wheels is 30 cm. What is its angular acceleration and what total angle will the wheel describe until it stops? How many turns does the wheel make and what is the length...

Homework Statement Beams AC and BD are light (no mass) and they're conjoined at B. Points A and D are fixed but frictionless. The radius of the wheel is R and the weight hanging on the pulley has the mass m. Homework Equations Fx=0 Fy=0 M=0 The Attempt at a Solution I'm stuck at the very...

Homework Statement The Sun rotates on its axis every 25 days. The sun currently has a radius of 7X10^8 m. When it expands into a Red Giant (in about 4 billion years) it will have a radius of 1.5X10^11 m. What will its rotational period be assuming the same mass for both, and they are both...

Hi, I am trying to work out the forces involved at the contact points in a design of a structure over a balcony wall. I have drawn up the cross section of the situation equilibrium, with a tolerance. I want to find out what forces will be acting on the structure and the balcony wall when a...

The general motion of a rigid body can be considered to be a combination of (i) a motion of its centre of mass about an axis, and (ii) its motion about an instantaneous axis passing through the centre of mass. These axes need not be stationary. Consider, for example, a thin uniform disc welded...

Will a body of given emissivity kept inside a perfect black body start behaving as a perfect black body?

Would a silver suite be a better body temperature decreaser than a mister of water? I cool myself off by spraying myself with water but I hear silver is the best conductor, is it better at conducting heat off my body than mist?

See attached photographs. For the car problem, I think the drag should be smaller than the forward acceleration but I'm not sure. For the Rocket question, I am pretty sure I am correct but I'm not sure why. The drag and the weight would both be in the down position.

Hi there, I would like to know how much force a full body jerk creates. You've probably all experienced this, when you were just about to sleep in, when suddenly your whole body jerks. I know that it is probably very difficult to measure the force excactly. But what might be the probable range?

I am a truck driver, the law requires me to restrain my load of 100kg, to resist a forward braking force (deceleration) of 0.8g. If, I took the 100kg load and tilted it (inclined plane), what angle of tilt, would be required to represent a force of 0.8g ? How does one calculate the angle...

Homework Statement In the figure (Figure 1) each of the suspended blocks has weight w. The pulleys are frictionless and the ropes have negligible weight. Homework Equations w = mg Forces cancel out, so Tension = weight (since they are suspended) The Attempt at a Solution For a (pulley) )...