Lost Definition and 552 Threads

Light (photons) that are reaching Earth after traveling billion of years, - the EM-spectre have become redshift. This means that photons must be losing energy. But energy can’t be lost, - so where is that “lost of photon-energy”?

Homework Statement In chemical reactions, when energy is released, mass is lost according to Einstein’s formula just as it is for nuclear energy (though the amounts lost are so small that for centuries scientists thought that mass was conserved). When a kilogram of coal is burned, it...

Photons which have experienced a change in frequency (red shift) due to gravity(or other red shifting affects), have necessarily lost energy. But total energy is conserved. Can someone please explain in what form is the energy lost? Also related to the red shifted light subject: Electrons...

Homework Statement An oscillator circuit is important to many applications. A simple oscillator circuit can be built by adding a neon gas tube to an RC circuit, as shown in the figure below. Gas is normally a good insulator, and the resistance of the gas tube is essentially infinite when the...

1. Homework Statement http://i43.tinypic.com/i1bq1i.jpg I need help with number 9 2. Homework Equations Wnet=change in KE Wnc=Change in Energy The Attempt at a Solution so I'm assuming the energy dissipated means the work done by friction? so work of friction is umgcos(15)*d...

[SIZE="5"]The need for philosophers in science.The greats. The greatest of the greats. Einstein, Lorentz, Darwin, Maxwell, Newton, Galileo, Aristotle. A girlfriend once used to say how much she admired the 1920’s when “men knew how to be men, and women knew how to dress.” We could probably...

Two magnet I put nearer to each other in such a way that there is a repulsive force between them. Both the magnets have some potential energy with respect to each other. I keep magnet in this position for a long time & so magnetic field became weaker & so magnet have less amount of potential...

Hey all, These are extra credit challenge problems given in my diff. equ. class, and I am in a bit of a rush to figure them out. I tried a few things, but I get lost toward the end. Here are the problems: 1) y'''-y''+y'-y=4sin(x) I did long division with the homogenous equation to...

Homework Statement a 6.0kg concrete block is dropped from the top of a tall building. the block has fallen a distance of 55 meters and has a speed of 30 meters per srcond when it hits the ground 1) at the instant the block was released what was the gravitational potenetial energy with...

Homework Statement A container having a volume of 40 L contains one of the following fluids att the given initial conditions. After a leak, the temperature and pressure are remeasured. For each option, determine the kilograms of fluid lost due to the leak, using Peng_robinson equation...

Mass to light ?? Some mass is lost in a star when it burns hydrogen to form helium ( 4H = 1He at more than 7000 C is'nt) ? .. Any calculation how much is lost ?? Even when u burn something which forms flame with are turning some mass into light right or wherelse is the light coming from...

Weve been working as a group on campus now for a few hours and we're lost on these 3. Our teacher did a horrible job explaining this material and the book doesn't do any better of one. A long, non-conducting, solid cylinder of radius 4.7 cm has a uniform volume charge density ρ = 2.1 µC/m^3...

and that's because i didnt finish the calculations on the second exercice i had a square root of something and i left it like this, she told me that i had to calculate the square root too, but i didnt have the time and that's why i left it like this if you were the teacher would you do the...

Homework Statement A student is running at her top speed of 4.7 to catch a bus, which is stopped at the bus stop. When the student is still a distance 38.2 from the bus, it starts to pull away, moving with a constant acceleration of 0.180 . Homework Equations This is where I am stuck...

Homework Statement 11.28 I have to solve acceleration given the equation for acceleration given the intial velocity=3.6 m/s, and the V equation V=.18V0/x 11.25 I have to find the distance it travels using the information in the picture below Homework Equations The Attempt at a Solution

Not getting symmetry at all. I keep reading over and looking for various materials on the subject, but I still can not seem to fully grasp it. Could someone explain what symmetry means in quantum mechanics in a way that a new learner can grasp? This question also applies to super-symmetry...

What happens to the "lost" energy in these situations? (a) A box sliding across the floor stops due to friction. How did friction take away that KE and what happened to that energy? (b) A car stops when you apply the brakes. What happened to its kinetic energy? (c) air resistance uses up...

Homework Statement A lost shipping container is found resting on the ocean floor and completely submerged. The container is 6.3 m long, 2.1 m wide, and 2.6 m high. Salvage experts attach a spherical balloon to the top of the container and inflate it with air pumped down from the surface...

Homework Statement Suppose you have a mass/spring system (with spring constant k) buried underground such that its relaxed (equilibrium) position is level with the ground. Then suppose someone takes a small ball of mass m and compresses the spring a distance xo below the mass/spring's...

Homework Statement A H2 was headed North and a convertible Mini Cooper was headed East. Due to faulty traffic signals, they collided, leaving a skid mark 7.6 m long at an angle of 51 degrees North of East. What was the initial velocity of each vehicle and, if the speed limit was 30 mph, who...

1. A Flywheel (A) mass 100kg and radius of gyration 1200mm rotates 150rpm clockwise. The knetic energy of this flywheel is to be reduced 20% by impacting a second flywheel B rotating at 80 rpm in opposite direction, such that they have the same clockwise angular velocity after inpact. A)...

Just a quick question about conceptual stuff. How is momentum lost in real life? Is it because of friction or heat? Yet that only affects kinetic energy, which means that momentum should still be conserved. So, what else is there?

Have you ever lost interest in physics?! I’m afraid I have:cry:. I mean I suppose to hand in my thesis last month, but after working as a TA and meeting lots of ‘nerds’ I just lost interest in physics, I know it’s stupid but I couldn’t overcome the feeling, and I don't know what causes it. it’s...

For collisions wouldn't the distance traveled during the collision be the same? The energy lost is from heat, sound, deformation, etc. but wouldn't the work done on each car be the same since during the duration of contact they have to move the same distance (as soon as they move different...

1. A projectile (mass = 0.17 kg) is fired at and embeds itself in a target (mass = 2.43 kg). The target (with the projectile in it) flies off after being struck. What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off after being struck...

Homework Statement A 70 kg base runner begins his slide into second base when he is moving at a speed of 4.0m/s. The coefficient of friction between his clothes and the Earth is 0.70. He slides so that his speed is zero just as he reaches the base. a) How much mechanical energy is lost due...

Homework Statement A 22.9-kg girl slides down a playground slide with a vertical drop of 3.29 m. When she reaches the bottom of the slide, her speed is 1.34 m/s. How much energy was dissipated by friction? Homework Equations I used \DeltaKE + \DeltaPE = 0 The Attempt at a Solution...

Hi guys i am currently a year 1 student and i am doing physics major and i am having a tough time now Even though what i am learning now is the basic of physics, sometimes i find myself lost during lecture and can't make any sense of what the lecturer is saying. Is this a common thing that most...

Ok so the rpoblem is A 2.20kg box slides down a rough incline plane from a height h of 1.63m. The box had a speed of 2.33m/s at the top and a speed of 1.90m/s at the bottom. Calculate the mechanical energy lost due to friction (as heat, etc.). and I am not sure where to even begin with this...

Homework Statement A 25.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 19.00 m. When she is partway down the slide, at a height h2 of 6.00 m, she is moving at a speed of 9.10 m/s. Calculate the mechanical energy lost due to friction (as heat, etc.)...

What is the effect of wind turbines on the aerodynamic of the wind system? Since energy is conserved, will excessive turbines lead to a leakage of wind energy and transformed into mechanical energy? [or concert to heat?] Also, what is the effect of the local pressure? Thanks in advance.

Homework Statement Homework Statement [/b] Hello. I'm trying to solve a non-linear problem and I have been working through the notes on this pdf to try and understand the method before I use it but I get stuck at one of the steps. The pdf is here: http://www.nrbook.com/a/bookfpdf/f9-7.pdf I...

Homework Statement The Attempt at a Solution I'm really new to this, and the professor didn't explain it well. IDK if I did that right so far, but I'm not sure what to do next. What does it mean by the units of .00256? Thanks

Wow it's almost straight out of Jurassic Park, or Jules Verne's novels. http://www.guardian.co.uk/environment/2009/sep/07/discovery-species-papua-new-guinea the giant rat: http://img198.imageshack.us/img198/5349/algratvolcanostill.jpg

Homework Statement Use mathematical induction to show that when n = 2,3,..., \overline{z_1+z_2+\cdots +z_n} = \bar{z_1} + \bar{z_2} + \cdots + \bar{z_n} Homework Equations \overline{z_1 + z_2} = \bar{z_1} + \bar{z_2} The Attempt at a Solution So help me get started on the...

Homework Statement the speed is doubled and the freq stays the same what happens to the wave length? this is my frist day in this class and i have no idlea where to go with this if someone could help me though this and tell me how to fig stuff like this out it would be great...

Is energy lost from photons when traveling through the air (eg: friction) to an object from a source such as the sun? If so or not, please explain it me simply. Thank you.

Homework Statement Solve the differential equation R\frac{dq}{dt} + \frac{q}{C} = v_0 R is resistance, q is charge, t is time, C is capacitance, and v_0 is the EMF of the power supply.Homework Equations First-order linear differential equation solving method The Attempt at a Solution This is a...

energy lost by speeding car while drinving on a soft surface how much more energy does a car need to continue driving at a constant speed if it sinks 1cm into a soft material. car weight 1000kg car speed 30mph friction is neglected

Heat question!??the amount of heat gained or lost by a substance is equal to Homework Statement the amount of heat gained or lost by a substance is equal to the product of its______ times the change in__________ times its__________ Homework Equations none that i know of The Attempt...

Homework Statement A 40.8 g ball of clay hits and sticks to a 3.41 kg block sitting at rest on a frictionless surface. What is the speed of the block after the collision if the initial speed of the ball of clay is 5.04 m/s? b)What percentage of the system's initial energy is lost...

Homework Statement Calculate the magnitude of the bending moment and shear forces at the centre of the beam shown in the attached figure Homework Equations The Attempt at a Solution For the shear forces I think its the sum of the vertical components, Bending moment = not...

Homework Statement A small piece of aluminum(atomic number 13) contains 1015 . (The atomic number is the number of protons; it determines the (positive) electric charge of the nucleus and, thus, the number of electrons in a neutral atom.) If the piece of aluminum has a net positive charge of...

Suppose the length of a pole is a random variable X, with mean m(x) and probability density function f(x). Poles are cut to obtain an exact length L. If the initial length of the pole is less than L, the entire pole is lost. If it is greater than L, the pole with be cut down to L, and the...

1. The diagram above shows the lowest four discrete energy levels of an atom. An electron in the n=4 state makes a transition to the n=2 state, emitting a photon of wavelength 121.9 nm (a)Calculate the energy level of the n=4 state. (b)Calbulate the momentum of the photon. The photon is then...

Homework Statement Okay, here it is: The wavefunction is psi=1*[1/sqrt(6)]*psi_1 + 2*psi_2 and I have to find the total probability (yes, there is a "weight" of 2 in front of the second part of the wavefunction). Homework Equations I know that psi^2 gives the probability, but I don't...

Homework Statement A search light is being used at the edge of a tank to find a lost key at the bottom of the tank. The tank is filled to the top with a fluid for which the index of refraction is 1.68. The key is 8.176 m below the surface and 6.84 m from the edge of the tank. At what angle...

Energy "lost" in rolling, sliding and torsion Hey everybody, I have a question concerning three states and the state of energy in them. 1. Rolling 2. Sliding 3. Torsion For example: If I have a steel cylinder with diameter d on an axis (no friction in the axis) rolling horizontally over a...

1. I am investigating how the initial height a ball is dropped from affects the rebound height. We have been asked to make a prediction about what we think will happen; however, we have not been given any guidance as to what we should write. Homework Equations To find the % potential...

Has charge (magnitude) [edit] lost some of its value since the time of the big bang? If so, what's the theory behind this?