bodies Definition and 523 Threads

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?

This is not really a homework question but i am having dificullty visualizing the problem and needed some help understanding, the solutions say " The moment about the x-axis due to the forces can be found using the z components of each force acting at their interesction with the xy plane (A &...

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...

Homework Statement Suppose I had a large sphere with 10 protons and 10 neutrons. Another sphere with 2 protons and 2 electrons. How many different electrostatic forces would be acting between the two spheres? What would be the likely net force between the two spheres in this example? How...

Given two bodies where GM/x^2=A and Gm/x^2=a, how might one model the acceleration of either bodies as a function of time? A simpler version of the problem involves one of the masses being stationary (just for the sake of simplicity), so that GM/x^2=A and Gm/x^2=0. A more complicated...

Homework Statement A block of mass m is connected to another block of mass M by a massless spring of spring constant k. The blocks are kept on a smooth horizontal plane. Initially, the blocks are at rest and the spring is unstretched when a constant force F starts acting on the block of mass M...

Homework Statement Hi Please, I am not sure about this problem. It reads this way: Two identical pendulums X and Y each consist of a small metal sphere attached to a thread of a certain length. Each pendulum makes 20 complete cycles of oscillation in 16s. State the phase difference in...

Homework Statement Hi I am struggling with this question. It goes like this: A rubber ball is dropped on to flat ground from a height of 2m. (a) Calculate how long it takes for the ball to first hit the ground. (b)The ball loses 10% of its kinetic energy at each bounce. Calculate the...

Homework Statement Hi Can someone help with this problem. 2 particles of mass 30g and 40g respectively both travel at a speed of 35m/s in directions at right angles. The 2 particles collide and stick together. Calculate their speed after impact. Homework Equations MaVa + MbVb =(Ma +...

Homework Statement Two black bodies, a sphere and a disc, are situated at the same distance a from the sun. Calculate the ratio of their temperatures. Homework Equations Stefan-Boltzmann law: U = \sigma T^4 The Attempt at a Solution At a distance a, the irradiance from the sun is U =...

Okay, please don't ask me why I would want to do the following; I'll try to explain.. I am writing a program and already have a module for computing 2D rigid-body and spring-mass (with only 32-bit integers, no less) which I've modified from Box2DLite. Now, for my application, I would like...

Hello everyone. I have a problem...I'm calculating natural frequency of a standing cylinder. In order to do that, I need the ke - equivalent spring constant of that cylinder. ke = (EY * s) / (h) EY is Young's elastic modulus for material cylinder's made of s is the cross section of...

What is the largest astronomical body in the Oort cloud? Do such clouds exist for most solar systems?

It is known that Maxwell’s electrodynamics—as usually understood at the present time—when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable...

Dynamics. Motion of 3 bodies Homework Statement Initially the system of masses is held motionless. All surfaces, and pulley are frictionless. At the instant after the system of objects is released, find the accelerations of m1, m2 and m3. Data: m1, m2 and m3 Homework Equations F=ma...

Hi, I have a physics assignment due, and I've been struggling with a particular question. I would really appreciate if anyone could please help. Homework Statement Consider the system below. The mp = 20.0 kg 'pulley' is a solid uniform sphere of radius of 0.250 m with the frictionless...

The formula that is applied to falling objects with disregard to any exterior forces except gravity is : d=0.5(g)(t^2) Can it also be applied to decelerating bodies, such as cars, with disregard to friction? Such as a car with an initial velocity slowing down to 0 m/s over a distance of 50...

Ok from my perspective we are theoreticaly close to being able to grow a replacement body. I feel that this will be a "killer app" because it seems harder and more difficult to fight ageing and genetic diseases in a body already damaged. So what do we do with the brain? Just transplant it or...

Fluid Mechanics -- Floating Bodies Homework Statement A solid block with specific gravity 0.9 floats so that 75% of the body is submerged in water and the other 25% sits in an unknown fluid layered above the water. Find the specific gravity of the unknown fluid. density of water = 1000...

Homework Statement A piece of metal turns red when at 1100K while a piece of quartz doesn't "shine" (i.e. emits in the visible range I guess) at this temperature. Explain this phenomenon knowing that quartz is transparent to visible light. Homework Equations None. The Attempt at a...

Homework Statement Assume that the tungsten filament of an incandescent 100 W light bulb can be considered as a black body. Estimate the percentage of the irradiated energy in the visible spectra. The effective area of the filament is 100 mm^2. There are 3 more questions in the exercise...

I wonder about the general solvability of the problem of two point masses, interacting via a central force, exposed to an external field. Some special cases seem easy: - interaction by a rigid rod - any interaction, but the field and interaction forces "decoupled" (example: two...

Homework Statement A vessel is sailing with a velocity of 11 knots per hour in the direction southeast and a second vessel B is sailing with a velocity of 13 knoths per hour in a direction 30 degrees east of north. find the velocity of A relative to B. Homework Equations The...

First of all I'm not sure this thread should be in this section or in the Thermodynamics one. I don't understand something. If I'm not wrong, the wavelength of photons used in microwave oven cooking is around 122 mm \sim 10^{-1} m, much greater than visible light photons (450 to 750...

Homework Statement Figure 5-60 shows a box of dirty money (mass m1 = 2.7 kg) on a frictionless plane inclined at angle θ1 = 28°. The box is connected via a cord of negligible mass to a box of laundered money (mass m2 = 2.4 kg) on a frictionless plane inclined at angle θ2 = 64°. The pulley is...

Can two objects overlap in space-time? Why or Why not? If so, what circumstances must exist? If not, by what mechanism are two objects deemed separate?

Hi everybody!How is it going! I'm having kind of a trouble trying to understand how to solve this following simple problem.If somebody is willing to help me i'll be very greatfull! I'll try to translate it from portuguese and hope everything written is correct. Homework Statement...

Why only the magnetic bodies can be strongly magnetized while other bodies like wood, copper, glass e.t.c are hardly affected?

In section 8 of Einstein's On the Electrodynamics of Moving Bodies Einstein uses the expression A(sq)/8 pi. He states this represents the energy of light per unit volume. Does anyone know how he derived this?

Hi, Given a rigid body, to keep the body equilibrium, multiple upward forces act on the body with each a known displacement from the center of mass. How can we calculate the upward forces? Now imagine we have a table, with 3 legs of neglible mass, the center of mass is at the center of the...

Homework Statement Say, there are two bodies, mass m1 and m2, initially at rest at infinite separation. They start accelerating towards each other because of gravity. Express the relative velocity of approach as a function of the distance between the two bodies. Homework Equations Laws...

Homework Statement A hand truck is used to move two barrels, each weighing 80 lb. Neglecting the weight of the hand truck, determine (a) the vertical force P which should be applied to the handle to maintain equilibrium when α = 35°, (b) the corresponding reaction at each of the two...

Hello, I’m glad that I found this forum, because there is a question that has been bothering me for some time, and maybe someone on a physics forum like this can set me straight on it. It concerns gravity and acceleration. I understand that when an object such as a space shuttle is...

I am trying to find the easiest and simplest way of calculating the distance that two celestial bodies would need to be apart, in order for those celestial bodies to never get closer or further away from each other. I have the values of the mass, density, radius, volume and gravity of the two...

I've been trying to find equations that model the effect on water of something falling onto it (a pebble for example), without much success. Do you know them or where I can find them? It's such a common thing, it suppose it's not that hard, I just don't know where to look. It's of course a wave...

This is a fairly simple question so I wasn't sure if it belongs here, but it is not a homework question. Just a question on something I'm reading. The book says there are N solid bodies with initial speed vi (i=1, 2, 3, ..., N) and final speed vi' after some shock to the system. The book then...

What force(s) are at work when a spherical object, rolling down an angled surface, tends to adhere to the surface, if only for a short while? Does such a thing exist or am I playing fast and loose with the laws of nature? Thanks

Hello, I was just wondering if an Impulse was exerted by one body on another if they collided but remained in total contact post-collision. The reason I ask is because my little I=F(delta)t indicates that there should be a change in time to calculate an impulse but in this case the 2 bodies...

I have created such a thread in the past but it was misinterpreted and I haven't been given the help I needed , this time I shall explain more about what is going wrong through a figure . sorry for my bad english. topic: when a 3d body is going at constant velocity in a straight line and...

Homework Statement At the instant shown, bar AB has a constant angular velocity of 25 rad/s counterclockwise. Dtermine at that instant a) the angular velocity of the rectangular plate FBDH, b) the velocity of point F Homework Equations Va = Vb + Wba x Ra/b The Attempt at a Solution...

Hello! I'm new so I hope I've posted in the right place One quickie please, if anyone can help me :-) I hope to get my mass estimates in units of h70-1 x 10{blah} Msun However! I have found some values in units of just x10{blah} Msun (*) Where they have used h50 in their calculations...

Homework Statement Three uniform spheres are fixed at the positions shown in the figure below. (m1 = 1.0 kg, m2 = 2.0 kg, and d = 0.60 m.) (See attached picture) (a) What are the magnitude and direction of the force on a 0.0250-kg particle placed at P? (b)If the spheres are in deep...

Why do "black bodies" emit light at all wavelengths when heated? Light emitted from an object is made of photons that are emitted when electrons drop into lower energy states. And there are only certain energy states in an atom that electrons can occupy, so only certain wavelengths (aka...

Please help me make sure I understand the following right. Or correct me in case of misunderstanding. ...explanation of the formation of the standing eddies... we may say that, as R increases and the convection of vorticity becomes more effective than diffusion of vorticity, more and more...

1. Homework Statement Ok I have been given an assignment and asked to answer questions about a lorry loaded and unloaded. the Text is as follows: An unloaded lorry of mass M kg accelerates from rest and reaches a velocity of 30mph in 10 seconds. It then travels at constant velocity for half a...

Homework Statement So, I'm creating a 2d graphical simulation of orbiting bodies. Right now I'm just working with 2 bodies, one stationary, but I would hope to extend this program to be able to include any number of moving bodies and have them interact accordingly. After combing...

Just like we have solar n lunar eclipse. What is the name given when all the bodies in our solar system alligns in one line? And what are the effects of it on earth?