Body Definition and 1000 Threads

Hi everyone, I'm having some difficulty comprehending "normal" transmission of stress/strain through a solid body and "shock" transmission of stress/strain. Imagine I have two bodies, one rigid - the other elastic. If the rigid body is fixed in space, and the elastic body is flying at the...

Homework Statement Will a frictionless body placed on the Earth move, and if so, describe it's path and acceleration. Homework Equations I was given no equations, but I believe that coriolis and centripetal forces would act on the body.The Attempt at a Solution I assume that we have to assume...

Homework Statement I need to calculate radiation power of ball in range 400nm-800nm. T=10000K d=1um. Homework Equations I think I need to use Planck equation and integrate that. My equation in link: http://imgur.com/XbAUwJ8 The Attempt at a Solution I look for equations and laws and try to do...

1. The problem statement, all variables and given/known See attachment , it only gives me length of rod and it's mass and radius of sphere and its mass and the place of the axis Homework Equations I=mr^2 The Attempt at a Solution I tried to get the moment of intertia of rod by integration from...

Hello everybody, I have a crazy idea in my mind, and I need help of someone who knows about physics ! I was wondering if it could be possible to lift a human body with fans on the ground. I know about vertical wind tunnel (indoor skydiving), but I thought more of a compact and homemade system...

Hi all, Would anyone be able to let me know what the average frequency is for the human body? Also, what is the average frequency of a home? What would be considered abnormal? According to the Ofcom UK Frequency Allocation Table it notes different frequency uses e.g. a frequency of 1,600...

Hi there. Excuse that I write it all in standard text but I don't know how to write it otherwise. I'll get right to the question and try to see if I understand the theory from the answer. Suppose we have a system of two electrons, one spin up and one spin down in a system with 3 possible...

Homework Statement At lunch, the Sun's thermal energy incident on the surface of the Earth is 1.4 kW/m^2. Given the radius of the Sun, R, distance from Earth, r, and treating the Sun like a perfect black body, calculate the total intensity of its radiation and determine its temperature...

A cylinder rolls on a horizontal, flat surface without sliding towards the left, so it must be rolling anticlockwise about its center of mass (CM). Suppose it slows down to a stop due to friction. What is the direction of the friction at the point of contact? Since it slows down, friction must...

Suppose we have a rigid body that rotates around a point P other than its center of mass, with point P being a point of the rigid body. This implies that there are external forces to the rigid body. If the external forces cease to exist(like we have an axis passing through P and we suddenly...

Homework Statement An object weighing 8.0 N is supported by two rope, which form the angles a and b to the horizontal, with tensions T1 and T2. angle a = 30 degrees angle b = 60 degrees I have calculated these values: T1 = 4N T2 = 6.93N How do I find the maximum tension of the obtained...

Homework Statement The occupation of each single-particle state with wave vector k =/= 0 in the ground state is given by nk = <0|bk†bk|0> where b and b† are bogoliubov transformaition. Find an expression for nk. bk = cosh(θ)ak - sinh(θ) a†-k bk† = cosh(θ)a†k - sinh(θ)a-k Homework EquationsThe...

Hello everyone, I've written a code using ode45 which describes the motion of a body m around a central one M (e.g a satellite around earth). I've done it with initial values that set the trajectory of the particle to be elliptic. Clearly, energy and angular momentum need be conserved in this...

Hello all, I have browsed this forum occasionally when I had questions and threads showed up on a search. I have been stumped by a problem, so I decided to create an account and see if anyone could help me out! 1. Homework Statement A coal barge 1000 ft long and 100 ft wide is submerged in a...

Can our body synthesize its own minerals and essential elements? I mean calcium, potassium, sodium, phosphorous, magnesium, zinc etc. I know we can have them from our food. Also, can they be stored just as glycogen stores glucose and fat tissue stores triglycerides etc?

We generally consider impulse during a colliion but if a body is simply accelerating e.g a car moving with a acceleration will it have impulse? If a body has an acceleration it may have a change in velocity there will be impulse and if moving with uniform velocity it may not have impulse. I am...

I was just wondering, what if an object is placed in our solar system, will it revolve around the sun? If yes, will it have a centripetal acceleration too?

Homework Statement The number density of 1H nuclei in the body is roughly 600 times greater than that of 13C nuclei. By what factor is the magnetisation M0 of 1H greater than 13C in the same external magnetic field? Homework Equations 3. The Attempt at a Solution [/B] Surely it can't be as...

1. Body of mass m = 3kg is accelerating with acceleration of ##\vec a = 2\vec i + 5\vec j m/s^2 ##. I need to find the resultant force ##\vec F## and the force's value. 2. Of course, the first equation that came to my mind is ##\vec F = m * \vec a## 3. I came with a possible solution for this...

Free body diagrams are where you simplify each object to a point and draw all of the forces acting upon it. I am having difficulty understanding it entirely and it would really help to just have a bunch of examples of free body diagrams. If you have a link to a bunch that would be great. I...

What would the Free Body Diagram of a Trebuchet look like (FOR THE SYSTEM)? Would it be comparable to a see saw/ teeter totter? I am aware of some of the forces at play, but I feel there is some I am missing.

I'm trying to understand the solution to an exercise. The solution claims that that the absorbed power of a black body from sunlight with an angle of incidence of ##30^\circ## is ##P=P_0\cos(30^\circ)## The reasoning here being to take the component orthogonal to the surface. However what...

Homework Statement I'm fully convinced that the zero values make sense, yet they are wrong, can somebody please explain why is that the case Homework Equations N/A The Attempt at a Solution Attempt in the image above

Hey there! I would really appreciate if someone could help me with the following problem. I didn't find it anywhere (textbooks, web...). Not only currents but also magnetized bodies possesses magnetic moment. I know that if the magnetized body is at rest in a constant external magnetic field...

I will start with an excuse, sorry english is not my main lengauge and i don't practice grammar that much, it is my first time in these forums so be kind, i hope i posted on the right forum thank you for the comprehension. When you move your arm for example do you generate a trail of vacuum...

Homework Statement Free body force diagram question, where I have selected the best answer but the diagram doesn't ring completely true (see diagram uploaded). I think mathematically the diagram is sufficient but it doesn't properly represent the situation. Do you agree? Homework EquationsThe...

Hello everyone, I came across this in J. Anderson's book "Fundamentals of Aerodynamics". "For the type of gases and liquids of interest in aerodynamic applications, the value of the shear stress at a point on a streamline is proportional to the spatial rate of change of velocity normal to the...

I ran into the following problem, and stuck for a couple of days now. I have a solid body, rigid and and has uniform density. Its mass M, the location of the center of gravity x_M, y_M, z_M and its inertia matrix is known: Jx Jxy Jxz Jyx Jyy Jyz Jzx Jzy Jz I have to write an algorithm...

Considering a body falls a free fall and g is changing, what is the formula of the height as a function of time?

Homework Statement The gauge pressure pg versus depth h is plotted in the figure for three liquids. For a rigid plastic bead fully submerged in each liquid, rank the plots according to the magnitude of the buoyant force on the bead, greatest first...

Let's say you have a good personal computer with these characteristics: i7-6700K, 32GB RAM, 256GB SSD, 2 x GTX 970 4GB And let's assume you can run your algorithms, software... for 24 hours. I wonder, if I would be calculating the orbital structure of an hydrogen atom with many electrons...

I was wondering if anyone can provide feedback on my free body diagram of two objects acting on each other. The question is asking for two separate free body diagrams. A force is applied to object 1, and object 1 pushes against object 2. Object 1 is on wheels and object 2 is in contact with the...

If I were to draw a displacement time graph of an arm rotating around it's origin at a constant radius meaning it is a constant displacement from the origin. Meaning the graph looks the same as one of an item that is not moving,how would you draw the displacement time graph of something moving...

Homework Statement In this problem you will do numerical computer calculations. A skydiver of mass 75.0 kg jumps out of a plane at an altitude of 30.0 km above the surface of the Earth. His parachute fails to open. Assume there is no horizontal motion and the initial velocity is zero. We...

Consider a free-falling object with known mass and center of mass being acted upon by four forces -- force of gravity at the center of mass, as well as three additional force vectors applied at known positions on the body. Is it possible to calculate, in closed form, the position and...

Homework Statement (a) A body of mass m is suspended from a vertical, light, helical spring of force constant k, as in Fig. 1. Write down an expression for the period T of vertical oscillations of m. (b) Two such identical springs are now joined as in Fig. 2 and support the same mass m. In...

I remember my teacher saying it to be the axis along the centre of mass but the centre of mass has all the mass concentrated in it and hence moment of inertia should increase as moment of inertia is proportional to mass?

Hi, I have a problem that I'm trying to solve and I'm not sure at all how can I proceed. If we have a metal rectangle (or maybe a rectangle-shaped hole in a piece metal), and we stretch this body a small distance, what is the shape of the top and bottom lines of the body? Can we say it is a...

Homework Statement Homework EquationsThe Attempt at a Solution I got the components of each force. I called the Force from BA "B" and the force from CA "C" and then the force going downward on D "W" FBy=sin30*B FBx=-cos30*B FCy=3/5*C FCx=4/5*C W=-500 ~~~~~~ ΣFx= -B*cos30 + 4/5C = 0 ΣFy=...

Homework Statement Log A weighs 20Kg is laid on a diagonal smooth plane with a diagonal angle of 27 37 degree, log A is tied by a rope to the head of the plane and there through a wheel with no friction the rope descend vertically to the bottom of the plane and through another friction-less...

a disc of mass m and radius r rolls down a slope of incline tan^-1 3/4. the slope is rough enough to prevent slipping. the disc travels from rest a distance of s metres straight down the slope. (i) show that the linear acceleration of the disc is 2/5 g. what i did was i first revolved the forces...

Homework Statement This problem relates to the two body problem of two rotating point masses, where one is much larger than the other. Equate the orbital energy per unit mass ##\epsilon## with the moments of momenta at the apses to get: ##\epsilon = -\mu/2a## Homework Equations The orbital...

Homework Statement A positive charge Q1 = 7.4 μC is located at a point X1 = -2 m, a negative charge Q2 = -9.7 μC is located at a point X2 = 3 m and a positive charge Q3 = 2.1 μC is located at a point X3 = 9 m. Draw free body diagrams for the electric force acting on Q1, Q2 and Q3. Find the...

In deriving the expression for the deflection Φ of light around a massive body, invoking Huygens' principle, Einstein arrived at the equation: dΦ/dx2 = dγ/dx1 where γ is the speed of light in units of c, and the xμ are space coordinates. How is this equation arrived at?

Homework Statement A positive charge Q1=7.4uC is located at a point X1=-2 m, a negative charge Q2=-9.7uC is located at a point X2=3m and a positive Q3=2.1uC is located at a point X3=9 A. Draw a free body diagram for the electric force acting on Q1, Q2, and Q3. B. Find the magnitude of the force...

Hi all, I am reading some materials on electrical parameters of a AA battery which give 1.5V and about 2000mAh. As my understanding, the 2000mAh means it will produce 2A if we keep taking current from the battery for an hour. 2A is huge current for human being. I wonder why it won't hurt the...

I wonder how were historically functions of the body organs determined? I mean how they dermined working of circulatory system , Nervous system, Excretory system etc?

Volume vs Circumference of a massive body. In the spacetime diagrams it is often shown that the space around massive bodies is warped in a way that seems to indicate the actual volume of a massive body is larger than 4/3 pi r^3. If you measure the radius from the circumference by traversing it...

Is there a criterion for a gradient of deformation tensor to be describing a rigid body??

Homework Statement A 250 kg box slides down the ramp and then across a level floor. The coefficient of kinetic friction along the floor is 0.20. A person see the box moving at 1.0 m/s(left) and pushes on it with a horizontal force of 140 N (right). How far does the box travel before coming to...