bodies Definition and 501 Threads

Does anyone know of a good mathematical reference covering the use of one-parameter group actions to model rotations of planets and/or other rigid bodies? Thanks in advance!

My boss and i were considering he following problem (see attached image): 2 unequal masses rotate an equal distance, r, about an axis. We both agreed that regardless of their angular position from each other (wether they were diametrically opposed or otherwise oriented, the 2 examples shown...

How would one go about calculating (as a first-order approximation) the gravitational time dilation generated by multiple point sources? When generated by one point source (M = 1\cdot10^{25}, r = 1, t = 1), I've got it down to: \tau = t \cdot \sqrt{1 - \frac{2GM}{rc^2}} \approx...

Homework Statement Two bodies mass m_1 and m_2 are a distance x apart. How long do they take to collide as a result of their gravitational attraction to each other. Homework Equations This question was asked in another thread which I found in a search. However the final answer was...

Homework Statement Hi. I am a newbie to the Physics forum. I am actually attempting to figure out a problem where there are two bodies forced to revolve around each other. The only constraints that would exist are the distance of separation between the two bodies is assumed to be constant...

Why do muscle cells have more golgi bodies than, say, cheek cells?

Hi I was ready a physics textbook and came across a quiz related to friction "What is the direction of the friction force on a crate which is on a truck moving towards east" . I think it is west, but I don't know if I am correct. As the crate is also moving with truck, the truck...

We all know this book... its is basically the SR as we know it. you can find it here ww.fourmilab.ch/etexts/einstein/specrel/www what i was looking for was how and on what basis back on 1905 the Albert figures out the speed of light is constant... all I get is this "Any ray of light...

Edit: Tried to post three times and forum kept adding the prompts. Removed Prompts. Homework Statement Three blocks are initially at rest on a level frictionless surface. At t=0s, a three identical forces are applied to a different point on each block. Each block is a rectangle approximately...

Do you know why potyviruses generate inclusion bodies as part of a translational strategy? I tried to find it on the web, but not many of them are that specific and hard to understand. thanks

So the situation is like this a ruler (of uniform mass) is pinned to a nail through its center. The has very little friction so it will spin but come to a stop. Initially it is at rest and is sitting perfectly horizontal (so that means the center of mass is at the center of the ruler). Now I...

Say you have 2 masses connected by a massless string, and another massless string is connected to the rightmost mass. A tension force T acts along this rightmost string, resulting in the string connecting the 2 masses to become taunt. In these cases, you can treat the 2 masses as one mass...

Two metal spheres (r2 = 2 X r1) have the same charge q on each of them separately. Now they are brought in contact. What will be the new charge distribution? My extension : What are all the factors that determine the new charge distribution? What if they are connected by a metallic rod...

Hello! The stem from this problem came to me when I was pondering how to describe the motion of two massive objects feeling the others' gravitational attraction (i.e binary star systems or something like that). Well this got ugly fast so I had to simplify a lot of things, and I finally got an...

Homework Statement Two bodies move in a straight line towards each other at initial velocities v1 and v2 and with constant retardation a1 and a2 respectively at the initial instant. What is the max initial separation between the bodies for which they will meet during the motion? (sqr ->...

According to my book the electric charge of large bodies like the Earth and the moon is pretty close to zero. But the Earth has poles and a magnetic field, which suggests that it isn't uniformly distributed at all. These two things SEEM contradictory to me, what is it that I am not getting? k

Hi, I was just going over some equations for velocity with respect to bodies revolving around the sun. I wanted to figure out the ratio of tangential linear velocity (i.e. speed) of a body when it is at its perihelion to its velocity at aphelion. In other words, I wanted to solve for...

I read that charge resides on the outer surface of a charged (electrically) body. Is it meant only for charged conductors or all charged bodies including conductors or insulators? What are the specific points with respect to conductors and charges other than (i) conductors allow current freely...

Forgive me if this is a noob question. I know there are no perfectly rigid bodies so that if you had a light-year long rod and pushed it, the other end would not move immediately because if it could, then information could be transmitted FTL. But, what if you pushed on a quark in the same...

how heat will transfer in fast moving bodies?

Working on some sci-fi and exploring the theory that there is redundancy in the human body, i.e., we could function with fewer cells, then fewer amounts of elements, and therefore less matter. Could we be “fine-tuned” and exist as a smaller version of ourself?

yeah that's what I call body heat! :smile: http://www.upi.com/NewsTrack/Quirks/2008/01/07/crematorium_plans_to_create_body_heat/4593/

How does heat tranfer in motional bodies? Homework Equations The Attempt at a Solution

Is it a myth that the bodies resistance to germs be "built up" by exposure? I'm not sure is this is more a medical question, but I'm thinking it's more of something biologists would address? When I see people criticized about eating things that have come into contact with unclean or doing...

[SOLVED] center of mass Homework Statement 2 bodies m1 and m2 are hanged from the ceiling with a thread with length L. the bodies are also connected to one another with a thread which length is equal to the length from the masses to the hanging point. around that thread there is a spring...

There is a point b/t the Earth and the Moon where the gravitational effects of the 2 bodies balance each other. How far apart from the center of the Earth is this point? Answer: x = 3.44 x 10^8 m (from the earth) or 3.82 x 10^7 m (from the moon). I have no clue what to do. I assume you would...

Homework Statement Does it make sense to talk about kinetic energy without specifying, which axis the body is rotation about? I mean, since K = ½ * I * w^2, I have to say that " ... the kinetic energy of the body around the x-axis is ...", right?

Homework Statement Ok, when talking about rotating bodies, we deal with the following accelerations - please correct me if I am wrong: A radial acceleration (a.k.a. the centripetal-acceleration): w^2*r or v^2/r. An angular acceleration given by dw/dt. A tangential acceleration given...

Homework Statement A triangular body changes orientation as the suspporting links rotate. At the moment shown, theta = 90 deg, theta_dot = 5 rad/s, and beta = 45 deg. Determine vA and the angular velocity of the triangular body. rB/C = 2j cm and rB/A = 5i cm Points E and D are fixed...

Homework Statement Point O is fixed in space. Gear 1 has an angular velocity of 20k rad/s, and Gear 2 has an angular velocity of -10k rad/s. r1 = 0.3 m and r2 = 0.2 m. What is the angular velocity of the connecting arm OA, and what is the speed of A? Gear 1 is larger than Gear 2. Gear 1...

Help me...PLEASEE.. I would like to know about: 1)Background/History:Kinematics of a rigid bodies - linear and angular velocity 2)Application Kinematics of a rigid bodies - linear and angular velocity in dynamics Please reply me A.S.A.P =(

The only formulas for forces due to a magnetic field have to do with a charged body. How can you calculate the force acting on an uncharged body? And if there is no force, why can you pick up a neutral paper clip with a magnet?

Say we have 2 bodies of m1 , m2 . The distance between them is a) r1 Ma=m1+m2 b) r2>r1 Mb=m1 +m2 In each case the mass was measured by an inertial observer . Is it true that Ma<Mb I saw this kind of thinking in measuring the energy neccesar to separate a nucleon from a...

Homework Statement A person in a hot air balloon that is rising accidentally drops a can of paint from the balloon. The balloon is moving up at a constant velocity of 4m/s, the distance to the ground is at the moment 4m. Find the time it takes for the can to drop to the ground. Homework...

Say I have two bodies, idealized as points with mass, in Galilean spacetime A^4. When thinking about the 2-body problem (just two bodies with interaction forces in the entire universe), one usually goes from the 3-dim. to the 2-dimensional problem using some special idea. I read the following...

Homework Statement Im having real trouble with drawing diagrams for virtual work. Can someone please, please help me! We were asked, in the diagram i posted, to find 1)vertical reaction at F, 2) all reactions at A, 3) bending moment and shear force at B using virtual work. i think i...

Can the distance between two bodies be calculated to prove they are gravitationally bound? Use two bodies with known mass.

Homework Statement a stone is dropped from rest into a hole. the speed of sound is 343 m/s in air. the sound of the stone striking bottom is heard 1.5s after the stone is dropped, how deep is the hole? Homework Equations kinematics equations The Attempt at a Solution not a...

Homework Statement A ball is dropped from rest from the top of a cliff that is 24 m high. From ground level a second ball is thrown straight up at the same instand theat the first ball is fropped. The initial speed of the second ball is the same as that with which the fist ball hits the...

Experiment Help! Homework Statement We were given this experiment in which we have to investigate the motion of a freely falling body on a fictitious planet. 2. Things we have to do (1) the value of the acceleration due to gravity on the planet, (sucessfully did it) (2) how the distance...

I need a formula(s)! I have a vehicle(semi) traveling on a 2% downgrade with a begnining speed of 60mph, no acceleration or braking on the downgrade. Adj "f" is .73 if that is needed. I need to be able to calculate the vehicles increase in speed in both time and distance increments. Doesn't...

Homework Statement It is possible to calculate the velocity of falling bodies (ignoring air resistance of course) using a gravitational acceleration constant. Assume: You don't know what the resistance is. The object started at rest. You DO know there is downwards motion. You don't...

It is possible to calculate the velocity of falling bodies (ignoring air resistance of course) using a gravitational acceleration constant. If there is some other resistance, other than air, is it reasonable to simply reduce the acceleration by some amount to account for that resistance, if...

The floor is smooth. Y and Z are in contact. The mass of the balls are m,m and 2m as stated. Assume all collision is elastic, what are the velocity of the three balls after all collisions?? Now, Y and Z are reversed in position. At the time of collision, what would happen for the three...

If I have two rubber coated kevlar balls, one is filled with air and the other has a gas like helium in it, if submerged underwater, would the ball with helium be harder to keep underwater than the air filled ball would be, or would they be equal in their buoyancy? Also is helium easier to...

Two indentical spheres with radius 15cm and mass 100kg are 6mm apart from echother in space. My problem is to find how long it will take before gravitational attraction will cause the two spheres to come together? What I have found out so far is: I have the gravitational force Fg= 7,12*10^-6...

It is known that radius of black hole is 2GM/c^2. And second radius is 3GM/c^2. (light ray at the second radius is not eaten but it circulate around black hole.) But, let us assume that we have body which moves almost with speed of light. 1. Are these two radiuses the same or approximately...

"Proper" accelerations and rigid bodies. In Special Relativity, the term "proper" in front of a property means, as I understand it, the value of that property as measured by an observer with test equipment at rest relative to the object being measured. Thus "proper length" is the length...

This is not homework, so I think this is the right forum. I am trying to write a program that simulates the heat transfer between, say two cubes of different volumes, heat capacities and thermal resistances. I know Newton's law of cooling just works dandy for say an object cooling in a fixed...

Hi all - I wonder if you could settle a dispute that's happening at a non-science forum? The maths itself seems complex, but the principle will be very familiar. Two bodies are identical in every respect, except for mass (e.g. a solid steel ball and a hollow steel ball of the same dimensions)...