bodies Definition and 523 Threads

What exactly did Max Planck assert regarding the discrete quantum nature of energy that was so significant to the observations obtained of black bodies, which contradicted the classical predictions of the time? i.e. the UV catastrophe? My overall understanding is flawed I wonder if you...

Is a wall rigid body or a non-rigid body? As per definition, a rigid body does not change any inter-molecular space on application of force but moves. But a wall does neither. So what is it - rigid or non-rigid?

Hi can someone please guide me to an explanation of axial deformation of indeterminate bodies and the method of forces in that too Thanks Chirag

Hello, I would like to try to "model" motion of two gravitationally interacting bodies. But from some "separated" point. I can find the trajectory of mass point to orbits around some other mass point from point of view one of them (using binets formula). But in this reference frame I am...

Homework Statement A body of mass 2.0Kg makes an elastic collision with another body at rest and continues to move in the original direction but with one-fourth of its original speed. What is the mass of the other body?Homework Equations Because it is an elastic collision I know that Energy and...

Homework Statement PS:The compound gear to the right is located inside a truck, whose engine rotates the driving gear with torque of 816 N*m. Assume that in the figure to the right, each of the smaller gears have a radius of 5.0 cm, and the larger gears have a radius of 25cm. Also, assume...

Homework Statement The upper portion of the crane boom consists of the jib AB, which is supported by the pin at A, the guy line BC, and the backstay CD, each cable being separately attached to the mast at C. If the 5-kN load is supported by the hoist line, which passes over the pulley at...

Homework Statement The platform assembly has weight W1 and center of gravity at G1. If it is intended to support a maximum load W2 placed at point G2,,determine the smallest counterweight W that should be placed at B in order to prevent the platform from tipping over. Homework Equations...

I am using a wikipedia page, Derivation of the Lorentz transformations and a lot of historical papers. To follow through I came up with my own transformations that do not contain the gamma factor: ##x^{'}=x-\beta ct## ##t^{'}=t-\beta \frac{x}{c}## When applying them to a waveform...

1. A steel ball of mass 0.400 kg is fastened to a cord 60.0 cm long and fixed at the far end, and is released when the cord is horizontal. At the bottom of its path, the ball strikes a 2.00 kg steel block initially at rest on a frictionless surface. The collision is elastic. Assuming the...

Hello everyone. In my computational physics class, I am supposed to use numerical method to solve for equations of motion of the Earth and moon orbiting the sun, at which I place the origin of my coordinate system. However, I have a physics related question. Before I pose the query, allow me to...

Why do celestial bodies follow different laws of physics than terrestrial bodies? A non-rotating object has a point on its axis, or axle, continually aligned with a point on the object. An axis is virtual, or imaginary; an axle is real and we live in a real physical world. In a real physical...

I've always thought of work done as being calculated by something like ∫F.dx whenever a force acts on a moving body. Another way of writing this ∫F.vdt. The non integral form of this equation (W = Fv) makes sense to me in the situation where the body is moving at a constant velocity as the...

For my own personal project I want to simulate our solar system on a computer program. I understand that the force applied on a body due to gravity can be calculated by dividing the product of the two masses by the square of the distance between them, then multiplying this value by the...

Homework Statement A small rock is thrown vertically upward with a speed of from the edge of the roof of a 30.0-m-tall building. The rock doesn’t hit the building on its way back down and lands in the street below. Air resistance can be neglected. (a) What is the speed of the rock just...

Homework Statement A boy launches a toy helicopter from the ground beside a building. It accelerates upward at 15 m/s^2. At the same time, another boy throws a rock down from the top of the building, which is 60 m above the ground. the helicopter and the rock collide at a height of 30 m...

Homework Statement Two railway trucks of masses m and 3m move towards each other in opposite directions with speeds 2v and v respectively. These trucks collide and stick together after the collision. What is the speed of the trucks after the collision? Homework Equations Conservation...

If I wanted to set up some initial conditions for a 3 body figure eight orbit, what would I have to set the position and velocity vectors? Say I have three vector inputs: initial position <x,y> initial velocity <x,y> mass of bodies <m1,m2,m3> The solutions for position use f=mi*x''...

Homework Statement Determine the reaction at C. Homework Equations The Attempt at a Solution i know i have to take the moment about line DB and thus resulting in ƩM(DB)= λ(DA X F) + λ(DC X RC) =0 where λ = DB/ DB however the book solved it differently. they instead do...

Homework Statement Three objects of equal mass, A, B and C, are released from rest at the same instant from the same height on identical ramps. Objects A and B are both blocks, and they slide down their respective ramps without rotating. Object C rolls down the ramp without slipping. Its...

I'm not talking about relativistic effects, just solid state physics. I'm wondering what determines the size of objects at the particle, atomic and molecular level, and especially how the constant c enters the equations? I suppose it depends from the strength of the molecular bonds which...

Homework Statement An opening in a floor is covered by a 1×1.2-m sheet of plywood of mass 18 kg. The sheet is hinged at A and B and is maintained in a position slightly above the floor by a small block C. Determine the vertical component of the reaction (a) at A, (b) at B, (c) at C.Homework...

Given two equal mass bodies, moving in opposite directions with equal momentum, attached by rope. When the rope becomes tort, what happens? Does the momentum cancel out and they become close to at rest? Or do they move inwards at some rate? This question came up after watching Gravity :). This...

Homework Statement The moon is smaller than the Earth and has a weaker gravity. On the moon's surface, the acceleration due to gravity is 1.6 m/s^2. You are on the moon and you throw a moon rock straight up. It reaches a height of 44 m. a) Find the moon rock's initial velocity. b)Find...

Homework Statement A brick is accidentally dropped from a window of a tall building and falls 160 m to the ground. How long does it take the brick to reach the ground? [b]2. Homework Equations [/b y=y initial+v inital +1/2 (αt^2) The Attempt at a Solution y=0+0+9.8 m/s^2(t)...

Homework Statement A diver steps off a platform 30m above the water. With what speed does he hit the water? Homework Equations v=intial v+at The Attempt at a Solution I reached an answer of 2.47 seconds, but I can't see how I got there anymore! Is this answer correct? Thank...

Suppose if travel towards the nearest star (alpha centauri) 4 light years away at 90% the speed of light does the distance between my spaceship and the star undergo length contraction? but i think in Wikipedia it its written as the distance undergo length contraction...

Homework Statement A block of mass m = 1.85 kg rests on the left edge of a block of larger mass M = 6.65 kg. The coefficient of kinetic friction between the two blocks is 0.310, and the surface on which the 6.65kg block rests is frictionless. Aconstant horizontal force of magnitude F = 20.10 N...

Hi, I am currently enrolled in a first year Physics for Scientists and Engineers course at a university, but I am a biochemistry student without a physics background. I am relatively certain that the problem is a forces problem, but there is a chance that it could be energy as we have just begun...

Homework Statement Consider two systems which together comprise an isolated system, but are initially not in equilibrium with each other. The temperatures of the two systems are T_1 and T_2 and the internal energies are E_1 and E_2. The systems are separated by a diathermal wall and only...

Hello, SCENARIO : I am a game developer and I am playing around with rigidbodies. I have a piece of wall which might get impact by an external force. The wall has in turn several other broken pieces (hidden for the moment) put up together to resemble this huge wall. Upon impact I switch...

Hey ya'll! I've come to the Physics Forum when I needed help with homework, but only to observe. This is my first time posting, and I'm glad to be here! I've got a question about, electrohydrodynamics. Recently, Elon Musk put forth his idea for the Hyperloop. For those who don't know...

Why are centre of mass of all uniform symmetric bodies at there geometric centre? We know the following result: "Consider a system of point masses m1,m2,m3... located at co-ordinates (x1,y1,z1), (x2,y2,z2)...respectively. The centre of mass of this system of masses is a point whose co-ordinates...

Vortex shedding is mandatory for all the bluff bodies ?? Vortex shedding is mandatory for all the bluff bodies ?? for example, flow over a low thickness flat plate with zero attach angle and flow over the very low depth dish antenna (like U shape) is there any shape (with particular...

If you see any mistakes in the following please let me know. This is for a paper. We often say that energy is abstract but it is certainly less abstract than say velocity or pressure by virtue of the fact that it seems to cause particles or bodies to displace other bodies. Undoubtedly...

I am trying to simulate and animate inverse dynamics. So I need to calculate torques. I started out by just taking a rod which rotates about its COM, applied a torque and then just used \tau=I\alpha to make sure I get back the same torque I applied. Next, I attached the rod to the ground with...

I have problems understanding the sense of reactive forces generated at pins / connections. Book is by Hibbler, I am posting links to images which will better explain my questions. The following links are concerning reactive forces. 1# http://i.imgur.com/0x62lp2.png 2#...

Homework Statement Homework Equations I'm dumbfounded by this problem. I can solve the (I think) harder problems with two fixed points and three rod segments. All the examples given in this book are of such "harder" problems and I have absolutely no example that resembles this...

I have a question pertaining to the motion of the center of mass (CM) of several connected bodies. Homework Statement Here is a picture of the set-up (green surfaces are stationary): The mass of the spring is zero. The mass of the disk is M1. The mass of the bar is M2. There is a pin...

Homework Statement I have 2 arbitrarily shaped conductors with charge Q1 and Q2 with potetials V1 and V2 respectively. I then short them (connect with a thin metallic thread) now i have to prove that the amount of charge that flows from one to the other is: Only dependent on the geometry of...

How can you test an area for radium cheaply, and how can you test your body for exposure. In other words how would you test a room? And what types of tests could you get yourself?

Homework Statement A body is found at 2:00pm at a temperature of 26°C, with a surrounding temperature of 18°C. Two hours later the temperature of the body is 21°C, when did the body die? T=Ae^(kt)+Ts where T is the temperature of the body A is the initial temperature k is a constant t...

I believe this is related to relativity, as it weighs in on how quickly information can travel through space; and I'm pretty sure this is the idea behind gravity's speed being that of light. However, I was wondering if you think it could be possible that gravity may be faster than light, as...

When a (say 50 meters) asteroid 'A' strikes a larger (say 500 meters) ‘equally hard’ asteroid 'B' at a small angle to the asteroid 'B' would have two vectors, one large vector parallel to the asteroid 'B', another second small vector perpendicular to the asteroid 'B'. ...

English is not my native language. My question is about what happens when we throw a ball on the floor. I understand why the ball bounces off it. But I have a question, I wonder why almost all the kinetic energy get back to the ball, rather than lost in the land, that is, why this energy is...

Hi all, I have a question about calculating the orbitals of bodies of mass in space (Newton's basic laws). I am writing a program to simulate the orbitals of bodies in space -- basically, you define the object's mass, size, location, and initial velocities and watch how they interaction via...

Can anybody please tell me how to represent a neutral antimatter body such as a planet or a star in the classical formulation of special and general relativities? Thanks.

If two bodies could be made to radiate at only one frequency a radiation heat pump could be made by having radiation sent by the colder body but having none received from the hotter to the colder by placing the colder body in a zone in a resulting inference pattern of zero net radiation. I don't...

Hello, I am first year mechanical engineering student and I am struggling with the concept of moment, rotation and angular velocities, accelerations of rigid bodies. Can someone recommend an article with problems or an excerpt from a book or something similar to help me. It would be great if...

Well, how big things can exist unseen? We did see Pluto - but very importantly managed to not see Eris till very recently. What else may we not see? Eris at 95 a. u. was found recently. The total luminosity of a reflective object decreases with fourth power of distance, so that we could...