bodies Definition and 501 Threads

Only rotating bodies have angular momentum? Is this statement false? I had read it somewhere that it is false that only rotating bodies have angular momentum, angular momentum = moment of inertia * angular velocity. Both deal with rotation. so how is the above statement false?

This here is actually an exam question from exam taken last week. I got near full credit for it, but I didn't do this problem properly. Even though I got a very high score, I feel I wasn't deserving of it. Haha, anyway, I still was a bit unsure of why the assumptions were made in the...

hey guys, got a few different questions for you, if you can answer any of them it would be greatly appreciated! 1. a barrel of mass 2.9x10^2 kg and radius of .5m rolls down a 43 degree ramp without slipping. what is the value of the friction force acting at the point of contact between the...

Hi friendz I m new to this forum I have a problem in a question which is as follows- If a body of mass m collides with a body of mass 2m it changes its direction of motion buy when it collides with a body of same mass m it stops and when it collides with a body of mass m/2 it does not change...

Imagine a diamond sphere radius of 1 cm traveling in space far from any heat sources. Embedded in the center of the sphere is a magic heater that can produce 0.3 W for an indefinite amount of time. If the emissivity of the surface is zero, what temperature does the sphere reach? Why? The...

Hello there. I would like to find the metric tensor produced by the existence of two massive bodies. Does the principle of superposition work for metrics as well? The first idea I got was to add the two metrics for each separate body in order to obtain the resulting one. Is this approach valid...

So I saw someone post this question on facebook and naturally being an Engineering student I'm curious to know now. I haven't done any Physics in a while so I'm not sure how you would tackle this one. The question was: "The power needed to operate your body is about 120 watts. Suppose your...

What happens when two objects of different charges come into contact? Do they distribute the charges per mass, volume, surface area or something else?

Two idential, finite sized bodies of constant volume and constant heat capacity are used to drive a heat engine- heat is taken from the hot (Th) body, work is done, and heat is ejected to the cold (Tc) body. Both bodies wind up at Tf (a) What is the change in the entropy of the system? (b)...

Suppose I have a disk that is 100,000 km in diameter. I attempt to rotate it at 1 revolution per second. Am I unsuccessful because the material on the outside edge would have to travel faster then light or am I successful because length contraction at the outside edge reduces the...

Homework Statement There are two bodies colliding Simulate the collision phenomena by numerical integration. (1) Confirm that the total kinetic energy is conserved if you ignore the damping forces. (2) Show that the total kinetic energy is reduced through collision if there exists any...

there's at least one company that sells these "earthing" or "grounding" pads that are connected to the ground port in the wall socket. Allegedly they help "discharge" human bodies, which generally have too much charge, causing inflammation in the body. whether or not charge in the body causes...

[Edit: ignore the below I realized what it represented later this afternoon. Probably because I asked and stopped thinking about it.] Jack is at the top of a hill that is 35 degrees. Jill is at the bottom of the hill on another slope which is 22 degrees. Determine the acceleration of the center...

Homework Statement I'm attaching a picture for the problem. Homework Equations F - N - K(that's my problem) = Ma K = m2a2 N = m1a (the acceleration is the same, since the rolling body pushes the m1 body forward) m1g - K = m1a1 (this is the acceleration in the y direction) a2 = a + a1...

Homework Statement Four 335 kg spherical masses are placed on the corners of a square at coordinates (0, 0), (0, 1.50), (1.50, 0) and (1.50, 1.50) where all coordinates are in meters. What is the net gravitational force on the mass at (0, 0) due to the other three masses? Express your answer...

If two bodies are moving about a common point, with one orbiting the other, in a completely circular orbit, from knowing just their periods (which are equal) and the graviational constants of each body times mass, how would you determine the radius of each of their circular orbits? You can get...

Homework Statement The question is regarding the stability of a large barge. Overall width=4m Uniform weight per meter length of M= 6327.19kg/m (This empty weight is uniformly distributed along the length of the barge. Center of gravity of the empty barge is at position G, 2m above the flat...

Homework Statement Force of tension externally is 150N [up] Acceleration is 2.99 m/s^2 [down] Mass A is the highest and is 4kg Mass B is attached to Mass A by a light (negligible) string, Mass B is 6 kg Mass C is attached to Mass B by a light (negligible) string, Mass C is 12 kg What...

1. A train has a length of 92m and starts from rest with a constant acceleration at t= 0s. At this instant, a car just reaches the end of the train. The car is moving with a constant velocity. At t=12sec the car just reaches the front of the train. Ultimately, the train pulls ahead of car and at...

Homework Statement I've already answered this question correctly after multiple tries but I am still confused about the method in solving these kind of problems. The two blocks (m = 18 kg and M = 88 kg) in Fig. 6-38 are not attached to each other. The coefficient of static friction between...

In solids there are crests and troughs. In highly polished surfaces there are molecular forces. But what creates friction during rolling where there is only line contact (in case of cylinder) or point contact (inn case of a ring)? I read somewhere that when an object is rolling it forms a...

Homework Statement An object has a weight of 250N, when weighed by spring balance. The same object is fully immersed in water, then the spring balance reading shows, 150N. How to determine the relative density of the object.Homework Equations Archimedes' principleThe Attempt at a Solution...

Me and a few friends of mine were discussing if mass plays a role in the speed of a free falling body. They argued that equal bodies (same volume, same geometry) with different weights (mass) would fall at different velocities. I defended that mass has no part on the matter, but only air...

Hi, guys! I've managed to implement a decent enough rigid body simulator for my 2D game using my sketchy high-school physics knowledge. Now I'm trying to pin some rigid bodies together. Connecting them with springs doesn't quite do the job. Too soft, the bodies drift apart. Too stiff, the...

Simple question, if the force of gravity is proportional to mass and distance, as in Newton's and Einstein's theories of gravitation, then why do people say that objects with two different masses accelerate at the same rate independent of mass on earth? Can Galileo's rule just be a practical...

Homework Statement At the instant the traffic light turns greeen, Stan Speedy starts from rest and accelerates at "a". At the same instant Kathy Kool starts from rest "d" behind Stan and accelerates at "5/4a" (not sure, but I think this is meant to be (5/4)a or 5a/4, my attempts with "5/4a"...

Hello, its my first time in this forum, I've registered because sometimes i have some physics questions during my free times (maybe not the best free time "sports" xD). The question is the following, according to the linear momentum conservation with elastic bodies, when a mass m1 with...

Can somebody tell me how to differentiate a large scale to a small scale? I want to know what he/she is based on. What if you had to compare the scale of large and small bodies using gravity and surface tension, what would be your first move?

Homework Statement Consider the study of the motion of a two bodies system interacting with only gravitational forces. If the two bodies (or even one of them) has not spherical symmetry, how will you proceed? Indeed the Earth and the moon does not have spherical symmetry mass distributions...

Hi. Keppler's third law implicates that the velocity of an object orbiting around our sun is directly dependant on the object's average distance to the sun... Afterall, if the velocity of be more irregular, then no constant would exist. I realize this probably has something to do with the...

I'm working on a basic 2D-"panelmethod" program. Currently it's "no-lift" but I would like to expand it to lifting bodies. The routines I'm using are loaned from my litterature and the program is working just fine for non-lifting bodies. It uses sources distributed over the panels to...

first off, thanks to any that respond w useful info :) the end answer i need to find on the first topic is how many atoms of hydrogen are required to propel a mass of "x" at an acceleration of 1g in space (assuming no gravitic influence) but i would settle for how to figure out what the fuel...

Dynamics of Rigid bodies. Help How so solve this? Help Loads 1, 2 and 3 are connected to each other with light unstretchable rope and are on a horizontal rough (friction μ = 1 / 3) plane. Loads weights are: G, 2G, 3G. Force F acts at first load with intensity F = 10G√2 inclined at 45 °...

What is solution to this problem any help is appreciated. Thanks Around wheel that can rotate around a horizontal axis is coiled (reeled) light unstretchable rope whose other end is tied load P. The position of the body is determined at all time with coordinate z =(pi)t³/3. Determine current...

Hi all, I've read somewhere that at least 20% of our galaxy's stars have planets orbiting them? But what is the share if we include all kinds of rocky bodies? How likely is it that stars suck in everything without leaving any leftover material what so ever? I'm curious because the Drake...

I have read in one book that it is possible if one body possesses greater similar charge than other .:confused:

Angular Velocities of rigid bodies at plane motion..Help me please Please Help for solve this problem.I really need it.It looks like is but not for me ... For the given positions OA=0,3m ; AB=0,6m ; BC=0,3m ; O1B=0,5m ; ω[SUB]OA[SUB]=2 s-1 of the part OA from the mechanism , shown in the...

Homework Statement [PLAIN]http://img135.imageshack.us/img135/1063/1763o.jpg Homework Equations IG = (1/12)ml^2 \sum Ma=(IG+m(rG)^2) The Attempt at a Solution I take the moment about A, which gives me the following: (4kg)(9.81m/s^2)(1m)=((1/12)(4kg)(2m)^2+(4kg)(1m)^2)\alpha...

I know that all bodies with a temperature above absolute zero radiate energy away as the following. P = AeσT^4 However, I wanted to know how you could find the frequency of the power being emitted just by knowing the temperature. For example, how would I find out how much heat I need to...

Is light the only type of information we get from intergalactic bodies? Is there any other type of information? Thank you

Homework Statement One body starts moving from point A so that in first min it goes 3 m/min, and in every next minute it goes 6 m more that in the minute before. Another body starts moving from point A 5 minutes later, going 54 m/min in the first minute and in every other minute 3 m more...

Homework Statement The piston is moving up at constant velocity 2.2m/s, the distance p is 1m, the distance q is 0.1m, the angle ɵ is 52 degrees. Find the magnitude of the acceleration of B Homework Equations Vb = Va + Vb/a Ab = Aa + Ab/a The Attempt at a Solution In...

Just totally confused which value to use to get the area moments of inertia with this question The ship was initially looks like this the mass of the ship is 5000 tonnes two heavy cargocontainers each of mass 73,370 Kg each assume that the ship has a rectangular waterline area, with length...

Hello, In DM, how can I create two separate bodies which are connected to each other? Apprently, ANSYS would merge them as one body by default. I've checked the manual and put one of them into frozen body, they did separate as two. However, I can't transfer the model to Mechanical, I...

Rigid, Non-Rigid and System of Rigid Bodies? Homework Statement Classify each of the following items as a rigid body, a system of rigid bodies, or a non-rigid body: a fishing pole, a diving board, a mechanical spring, a bowling ball, a baseball bat, a system of gears, a slider block system...

Do the sun, moon, Earth etc lie in the same plane? I mean are they at the same level or some bodies are above/below others? If yes than why?

Scenario: Let's say I lived on planet A (which was massive), which orbited planet B (which was also massive) so closely that upon looking up into the sky, planet B would fill most of what we would normaly see as being blue sky. Living on such a massive planet has some probolems; e.g being...

Hello -- I want to solve a very general type of minimization problem. I have 2 rigid bodies (e.g. molecules) which are exerting forces on each other, and I want to minimize the interaction energy (e.g. from a molecular forcefield with terms for things like Coulomb, van der Waals, etc). In...

Homework Statement Water bath whose walls are vertical and the bottom of which has dimensions as shown in line with a dip in the husband and wife. The pool water level rises then 6.4 cm. Homework Equations What are the bodies of the couple's total volume in liters. The Attempt at a...

Homework Statement In a two-dimensional space there is a system of two bodies, masses M1, M2, and coordinates (X1,Z1) and (X2,Z2) I have to find total mass, its coordinates, inertia momentum, and angular momentum Homework Equations ... my memories help here, obviously not so good ... The...