Body Definition and 1000 Threads

Hello, Recently I've been researching how to add velocities in a relativistic way, very interesting stuff. But every website I read uses a three body system to explain it. Object A relative to object B and object B relative to object C. I've spent a few hours looking and this is the only...

I am considering the gravitational time dilation at the centre of a spherical, non-rotating body (such as the Earth). The usual formula for gravitational time dilation is √(1-r_s/r) where r_s is the Schwarzschild Radius and r is the radius of the clock compared to one at infinity, however, this...

Hi all, Suppose we go in space where no gravity and friction exists. If there is a bar, in say - horizontal plane and we apply a force at one end of the bar, in this plane and perpendicular to the bar. Will that bar rotate and translate or it will only undergo pure translational motion...

We have a frictionless hemisphere M,of a radius R and a body m on the top of it.We give to the hemisphere a horizontal constant acceleration W and consequently the body begins to slide down the accelerating hemisphere.What is the relative velocity of the body in respect to the hemisphere when...

Hey guys , I've been searching for the codes / standards relevant to District plumbing (Road drainage , District Drainage , District water supply systems ) . Thank You for any help .

I always wonder about our human body in space without any suits. I don't know exactly what happens but i want to know which has been a interesting question to me right from my past. What will happen when a human body is exposed to space without any space suits?

It just occurred to me that in the right gravitational field, say, in a low orbit 100 km from the core of a neutron star with a mass equal to that of the sun, an orbiting object's center of gravity is somewhat noticeably displaced from its center of mass. Specifically, 1 meter closer to the...

$${\rho}({\lambda}) d{\lambda}=E({\lambda})*f({E(\lambda}))*D({\lambda})d{\lambda}$$ $${\rho}({\lambda}) d{\lambda}$$ is density of radiative energy, $$E({\lambda})= k_BT$$ is the energy of an atom vibrate in 3D, $$f({E(\lambda}))=1$$ is the probability distribution. Equals to 1 because we...

Homework Statement A circular disk with the mass m and radius r is hanging from two ropes with length l when suddenly the rope ED snaps. For this moment, find: a, The angular acceleration for the rope OB, the angular acceleration for the disk b, The force T acting in OB The Attempt at...

Homework Statement A solid cylinder is dragged over a surface by a constant force F that has an angle θ with horizontal. It rolls without friction around its symmetrical axis. The mass is M and radius is R and moment of inertia is I=\frac{1}{2}MR^2 The cylinder rolls on the surface without...

I have to measure the size of a cavity of a animal body(s). What is more important I need to measure it on several bodies and compare the results. The cavity is small and contains liquid. That liquid can be extracted and that sets the volume of cavity to 0. It's important to note that the...

Homework Statement Homework Equations M=FA Equlibrium condition= net Fy=0 net Fx = 0 Total Moment=0 The Attempt at a Solution I need help with the body diagrem The D circle thing is what? is that a roller?

Homework Statement http://postimg.org/image/4lvunjeoz/ Solution: http://postimg.org/image/v1d7gilef/ When you have to calculate the internal forces at a point, how do you decide which forces are included in the free body diagram? For D, why isn't the rectangular bit of the distributed load...

How does our body absorb the force from falling? And if we roll or bend our knees while landing why is the force felt by our body less? Can somebody explain?

Hi, every time I hear any website/TV program/person mention the percentage water composition of the human body it varies tremendously. 90,80,85,70,53. What is it? any help appreciated. Thanks

In rotation motion do points through which the axis passes also rotate or are they stationary?

Homework Statement The system consists of a 20-lb disk A, 4lb slender rod BC, and a 1-lb smooth collar C. If the disk rolls without slipping, determine the velocity of the collar at the instant theta=30 degrees. The system is released from rest when theta= 45 degrees. Homework Equations v=wr...

http://www.nasa.gov/content/goddard/hubble-sees-asteroid-spouting-six-comet-like-tails/#.UnvGoHemYRc Hubble photos http://www.nasa.gov/press/2013/november/nasas-hubble-sees-asteroid-spouting-six-comet-like-tails/ NASA press release

Inertia -- Moments of Inertia of a rigid body (different axes) Here is the problem http://imgur.com/pL6Bdgw So I missed class today because I was studying for a genetics test. I don't need the answer or anything but I was wondering what the general rule for inertia that I would use for...

Hey all, new to the forum. Had a tough question that I was trying to work out about an orbiting pulsar and the doppler shifted pulse period. So, if we have a pulsar orbiting some central object in circular orbit, with a constant orbital velocity v, and a pulse period of P_0, how can we write...

This may be a stupid question, but could any of you help me with the force body diagram of a person running? Before the foot hits the ground, once the foot hits the ground, and after the foot hits the ground? I'm having trouble trying to figure out what forces are being applied to the person...

Hello, I have been assigned a project to find a device to improve on, and one of the tasks is to create a force body diagram. I have a little bit of confusion when it comes to drawing it because if I'm writing the paper on shoes, and how it improves the movement of the feet, how will the free...

Hi, I know that the drag force on an object: Fd= 1/2 . ρ . v^2 . Cd . A where A is the reference area. But in the case of a streamlined body, I don't know what will be taken as the reference area. Should it be the largest cross-sectional area of the body?

Assuming no other compounds are initially present, what would happen to a body of Earth's mass, orbiting the sun at Earth's distance and speed, which is entirely composed of water? Assume that it just blinks into existence, and initially all the water molecules are arranged in a liquid sphere...

I am studying Floatation in school and I have some doubts. I get that if an object is denser than the liquid its placed on, it will sink, and if it is less dense then it floats. But what happens when the density of both (the object and the liquid) are same? Will it float or sink? My notes say...

Homework Statement http://postimg.org/image/i7phx5pp1/ Im trying to draw an FBD for this, but I don't know how the treat the distributed load or what forces the thing at E contributes. Is it some kind of support? For the distributed load, I don't know what part of it the 800N/m and...

Homework Statement Calculate the volume of a body given by plane ##z=0## and ##z=1## and ##x^2+y^2+z^2=4##. Homework Equations ##detJ=r^2sin \theta## for spherical coordinates The Attempt at a Solution ##V=\iiint_{T}^{}dV=\int_{0}^{2\pi }d\varphi \int_{0}^{1}dz\int_{\theta...

1. The question I'm struggling on has been answered on here before but with different values. Here is the link to the question https://www.physicsforums.com/showthread.php?t=344213 but on mine I have a 1.9kg object and F1=5 and F2=2. I figured out that the Y components are 0 for both of...

Homework Statement Two blocks are stack on each other. The lower block has a mass of 6.8kg and μs=0.34 with the floor. The top block has a mass of 3.4kg and μs=0.65 between the two blocks. A force of 18N is being applied to the top box to the left. What maximum force can be applied to the...

What is axial rigid body motion? Is it along Z-axis?

Homework Statement As the picture says, we are trying to find the reaction force on the bearing at A: We are given: M(block) = 26.1kg M(bar) = 8.7kg L(bar) = 1.8m V(block) = 6.2m/s Homework Equations What I have attempted the solution with are: ƩF = ma ƩM = Iα I0 = (m*L^2)/12...

Homework Statement A long slender rod has a mass of 0.66 kg and a length of 648.0 mm. The friction torque at the hinge is 0.41 Nm. What is the angular acceleration of the rod when it is 38 degrees below the horizontal? Homework Equations The Attempt at a Solution Torque =...

Hi All, I have a very simple question on a calculation, I would not doubt it correctness if it were not for the fact I am told by a colleague it is wrong, and I cannot see why (good job college times are gone). We have a cylinder of length L, density $$\rho$$ constant along the cylinder, one...

Hi every body! I'm a new guy here, and want to applologize for my Not perfect English. From the name of the topic you can understand what 'm trying to do here. ok here is an exercise: We have tennis ball m=57gr. and diameter of the ball D=6.7sm. from the start point coordinates Xo=0 & Yo=0.3m...

I wasn't sure whether to post this question in biology or physics. I'm stumped on a couple experiments. Here are the basic experiments. I have people wash their hands and dry them off and then hold onto the probes of a volt meter. To my surprise some people give a reading as high as...

Carbon (18%) Hydrogen (10%) Nitrogen (3%) Calcium (1.5%) Phosphorus (1.0%) Potassium (0.35%) Sulfur (0.25%) Sodium (0.15%) Magnesium (0.05%) Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%) Lithium, Strontium, Aluminum, Silicon, Lead...

Okay guys, a different one for you. I am in the planning stages of building a structure that will simulate a motor vehicle collision. The process would be a motor vehicle will be hoisted to a specific height and then dropped. The height, and the weight of the vehicle will determine the...

Archimedes principle of the force of upthrust = weight of water displaced by the body immersed , but is this law independent of the shape of this body. If we use the idea that the upthrust = P*A on the lower side - P*A on the upper side , if we use it on a rectangle or a square , the only change...

I am currently working through Griffiths' textbook on quantum mechanics. The hydrogen atom was first modeled as a one body system with the proton fixed at the origin. In this case the potential was given by Coulomb's law, V(r) = -\frac{e^2}{4\pi\epsilon_0}\frac{1}{r} \ , where r is the radial...

It should for nitpicky convenience's sake, be pointed out that unless the point we choose to calculate the moments around is the C.M of the rigid body, or that the the point moves parallell (including being at rest) to the motion of the C.M, we get an additional term on the RHS.

When a Rigid body is said to be in planar motion, if all all the particles in the Rigid body moves in same plane and these planes are parallel to each other. I think i misunderstood this definition especially the particles moves in same plane and these planes are parallel to each other...

Why can't the atoms along the edge of a body centred and a face centred structures touch each other? Is it something to with the reasoning that somehow if they were made to touch each other then we would not be able to get the face centred and body centred structure?

Hello! I am hoping someone could help. I have no idea where to start on this, and have been flipping pages for an hour or so trying to figure it out. Find the spectral range Δλ over which a blackbody's intensity B(1/2) is brighter than half of its peak value B(peak). (In other words, find the...

Here is the question: I have posted a link there to this topic so the OP can see my work.

Hi, I've got a simple question regarding the maximum of the spectral energy density in Planck's black body radiation. It turns out that if you calculate which frequency has the most power associated with it (i.e. maximize R(\nu)), then you do it with wavelength as well, and compare, they're not...

http://en.wikipedia.org/wiki/Dashi-Dorzho_Itigilov Is there any explanation for this? Maybe he pumped himself full of some kind of chemicals before he died and told them to exhume him, considering he knew medicine and pharmacology?

I have a question regarding forces in meniscus. Lets assume we have capillary 1cm in diameter. We pour some water into the capillary. We will observe concave meniscus. If we add some water (so water level exceed the height of the capillary) we will observe convex meniscus. Not let's...

Suppose a block of mass 5 kg is resting on a horizontal surface and coefficient of static friction between block and surface is 0.2. If the block is pushed against a vertical wall with a force of 200 N, will the static friction oppose the force? The body has no intention of moving as it is...

Could there be complex life somewhere in the universe with body temperatures averaging 80 degrees F? I am curious if life of some kind could survive a body temperature that low and function normally.

This is not a joke. Is it by all accounts impossible to do this, supposing that an artificial heart with artificial blood transport systems (that provide oxygen and all needed nutrients) were used to keep the cells from dying. Also, assuming the brain was yours, what would it feel like to...