Thermal energy Definition and 199 Threads

Homework Statement An ideal gas is at 40°C. The gas is cooled, reducing the thermal energy by 35%. What is the new temperature in °C?Homework Equations I'm not sure there is one? The Attempt at a Solution Since, in an ideal gas, thermal energy is proportional to temperature, I multiplied 40°C...

Homework Statement An ice cube at its freezing point is placed in nested Styrofoam cups which contain 240g of water at 21.5 degrees C. If the final equilibrium temperature when the last trace of ice melts is 15 degrees C, what was the mass of the ice cube? Homework Equations mCΔt = -mCΔt...

Homework Statement While forming a 1.5kg aluminum statue, a metal smith heats the aluminum to 2700 degrees C, pours it into a mould, and then cools it to a room temperature of 23.0 degrees C. Calculate the thermal energy released by the aluminum during the process. Homework Equations Q =...

Homework Statement A 1.0 sample of nitrogen gas (diatomic)is heated at constant pressure from 300K to 420K, Cp (nitrogen) = 29.1 Jmol-1°C-1 The thermal energy transferred to the gas is? 1. 8370 J 2. 12,200 J 3. 34.90 J 4. 3590 J 5. 12.20 J Homework Equations KE = 1/2mv2 =...

Homework Statement Two cars collide head on while each is traveling at 80 km/h. Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car? You can assume that each car's specific heat is that of iron. Homework Equations...

This isn't homework, so i thought it could go here. 1) What has thermal energy but not heat? 2) What has heat but not thermal energy 3) What effects angular momentum?

My editor friend is questioning the following passage in a book. Does this sound right? In particular, they seem to be making a distinction between "heat energy" and "thermal energy".

So we were studying about different types of heat transfers, conduction, convection, and finally we learned about radiation, it was sort of confusing, so I am going to write stuff, and hopefully someone can see what i wrote and see if its correct. basically the book says 'Radiation...

How would someone define thermal energy? My view is that it is the internal energy of the object e.g potential and kinetic energy. But from what I understand it can also be the energy transferred from one object to another, this is where I get confused. Dose the term thermal energy aka heat...

Hello, My apologies for making my first post a question but I was wondering if anyone could suggest an engineering degree which would be most suitable for a career with energy, specifically thermal energy and external combustion systems. I was technically a junior and had to take an session...

Hi, I need a way to convert kinetic energy into thermal energy as well as the specific heat of the entire Earth's atmosphere. The idea is to see if the heat generated by many meteoroid fragments could possibly account for any climate change. Thanks.

Postulate a parcel of air within the larger atmosphere. The air above the parcel is cooler than the parcel, while the air below it is warmer. The parcel is emitting photons to both the overlying and the underlying layers of air and simultaneously absorbing photons from both layers. Both sets...

It's not really homework, it's more of my own testing of a hypothesis, but I don't really know where else to put it. I need a way to convert kinetic energy directly to thermal energy as find out how much thermal energy it takes to raise the temperature of the atmosphere 1 degree, or I guess...

So I am doing a second year thermodynamics course and would like to know. Do we just have to remember (5/2)PV for a diatomic gas, why is it 5/2 and also what is it for a monatomic gas. Also would we have to remember more complex ratios for exams? Cheers

Homework Statement During the game, the metabolism of basketball players often increases by as much as 30.0 W. How much perspiration must a player vaporize per hour to dissipate this extra thermal energy? Assume that perspiration is simply pure water and that perspiration starts at...

Homework Statement I ask this because my initial assumption was that work done by a non-conservative force (friction in this case) is also equal to thermal energy. However, in my book, it gave an equation with W = Emec + E thermal. They also had an example where they added up the work and...

If I have an object say a 1kg lump of metal. it is at a temperature of say 20c. I then take that object and raise it and place it on a shelf, does it lose any thermal energy due to the new height, In other words does it cool down for no other reason than being raised to a different elevation...

A quartz tube contains one mom of gAs at 20 deg c. The gas is heated at constant volume to 300 deg c. How much thermal energy is transferred to the gas? If the same amount were heated at constant pressure, how muh energy would be required? I know how to solve this for constant volume using E=...

Homework Statement Suppose a cup of boiling water (m=250g) instantaneously cools to room temperature (25°C) with the liberated thermal energy going into translational KE. How fast will the cup fly off the table? Assume the water molecules have 18 degrees of freedom. Homework Equations...

I want to propose an interesting thought experiment, but don't want to A/ make a bigger fool of myself than I normally do B/ well that's about it really The premise behind my experiment is that rising steam does not lose thermal energy if we ignore thermal losses both radiative and conductive...

According to my textbook... Thermal energy is the kinetic energy of the component particles of an object and is measured in joules. Heat is the thermal energy that is absorbed, given up or transferred from one object to another. But later on the book there is a small chapter called...

Hello, kinetic energy is in some cases a bit of a mystery to me, I've made several assumptions about these things. But some of those assumptions seem to conflict a bit with what seems to be happening, so I thought I'd throw these assumptions out here to maybe hear where I'm wrong. Any comments...

Homework Statement In the diagram given, you pull upward on a rope that is attached to a cylinder on a vertical rod. Because the cylinder fits tightly on the rod, the cylinder slides along the rod with considerable friction. Your force does work (W = + 100 J) on the cylinder–rod–Earth system...

In classical thermodynamics, if we dissipated the kinetic energy of an object as thermal energy, then we would increase the entropy. However, let's say we took 90% of some thermal energy in a reservoir, and converted it into work, and 10% of that is converted back into thermal energy after 1...

In my thermo class I'm currently taking, the professor constantly says thermal energy cannot be completely converted into energy of motion. Just to be clear, I'm not arguing this point. I'm just wondering why we say that, when earlier in the course it said that thermal energy at the...

Dear all, I am not an expert of Chemistry and I would like to know if there is a reversible reaction that can be activated only by thermal energy. The result of the reaction should be something which can be brough again to the initial state, releasing again the thermal energy stored. I was...

Homework Statement HELP with physics homework, thermal energy? I cannot figure out how to solve this problem, can someone show me how? A small engine pumps 100 liters of water from a well 300m deep. What would the change in temperature be for the engine 20 liter cooling system (filled...

Hi, :smile: While running, a person generates thermal energy but maintain approximately constant temperature: Distinguish between the terms: Temperature and Thermal Energy I know temperature is a measure of the average Kinetic Energy of molecules but I always get confused when it comes...

i have a question: In an Insulated Vesse, 250 g of ice at 0 degree Celsius is added to 600 g of water at 18 degree Celsius. Find: a) Final temperature of the system. B) How much ice remains. PLEASE POST THE WAY HOW TO DO THIS QUESTION :D

Homework Statement What are the factors that determines the thermal energy of a gas in a 3d object like a box Homework Equations The Attempt at a Solution I think thermal energy can be referred to as potential energy and also kinetic energy inside the box. If they are essentially...

Hey, what are the most efficient/effective ways you know of to take thermal (heat) energy and convert it into either electricity or mechanical action in a portable form? I was thinking peltier devices, but turns out that only has an efficiency of about 10-20%. Steam power is another...

Homework Statement The rms speed of the molecules in 1.2 g of hydrogen gas is 1800 m/s. What is the thermal energy of the gas? Homework Equations m = Mass of 1 H molecule: 1.67 x 10^-27 kg N = Total # of molecules = 7.19 x 10^23 molecules c = rms speed The equation provided by my...

This is my very first post... :) I found some help here: https://www.physicsforums.com/showthread.php?t=277092 But I have a difficulty in sloving second and third part Homework Statement The figure shows(check the link) a thermodynamic process followed by 1.90×10^−2 of hydrogen (link to...

There seems to be considerable confusion in the scientific community about thermal energy and heat. I have read several textbooks on thermodynamics and several posts in scientific forums and they certainly don't agree on what is heat and thermal energy. For some: thermal energy is the kinetic...

haw can i calculate the thermal energy (watt or BTU ) of the hot air (or the exhaust air of the chimney) according to the following : Temp. : 250 C hot air flow rate : 11 000 m3/h thanks

Homework Statement An ideal gas is at 20C. The gas is cooled, reducing the thermal energy by 35%, What is the new temperature in C? Homework Equations None in particular. The Attempt at a Solution 35% of 20C is 7, 20-7= 13C

i want to try use heat energy to power a small device, but i also want to be able to store some energy for use at a later stage... how could i go about doing this? also it needs to be as small as possible, and also very cheap id guess that it could be relatively simple to do considering i just...

Homework Statement the roller coaster is 94.5m high at its highest point. what is the maximum possible speed of the roller coaster? the roller coaster's actual maximum speed is 4.1m/s.what percentage is lost to thermal energy due to friction? Homework Equations Wnc= Efinal-Eintial the part...

Homework Statement A chain of metal links with total mass m = 7 kg is coiled up in a tight ball on a low-friction table. You pull on a link at one end of the chain with a constant force F = 52 N. Eventually the chain straightens out to its full length L = 0.8 m, and you keep pulling until you...

[b]1. A 1300 N crate slides 15 m down a ramp that makes an angle of 40 degrees with the horizontal. [b]2. F therm = Fk\DeltaX [b]3. I understand how to solve this with the coefficient of friction given, but how can I without the problem stating \mu?

Homework Statement 300 g of water whose temp is 25*C are added to a thin glass containing 800 g of water at 20*C. What is the final temperature of the water? Homework Equations deltaE=mCdeltaT The Attempt at a Solution Here's what I did: deltaEsys=mCdeltaT [300g (4.2...

Hello! I was wondering if someone could take a look at this idea and tell me if there is something wrong with it: In attempting to shut down every part of a hypothetical spacecraft except some sort of highly insulated crew pod, the total amount of heat produced over a period of time is...

I am a first year Physics undergraduate. My question is with regrads to thermal energy. Many people define thermal energy as kT and equate that with the kinetic energy. In other instances, they equate 0.5kT with the kineitc energy. I am thoroughly confused about this. What is thermale...

This isn't really a homework question per se. I'm studying for my MCAT and I'm having trouble trying to firmly get down some of the concepts in thermodynamics. As far as I know, heat is the means of energy transfer that isn't work from one substance to another due to a difference in...

[b]1. Homework Statement : A power station with an efficiency of 0.3 generates 10^8 W of electric power and dissipates 2.33 multiplied by 10^8 W of thermal energy to the cooling water that flows through it. Knowing the specific heat of water in SI units is 4184 J/kg°C, calculate how many...

Homework Statement A gas is compressed from 600cm3 to 200cm3 at a constant pressure of 400kPa . At the same time, 100J of heat energy is transferred out of the gas. What is the change in thermal energy of the gas during this process? Homework Equations Express the answer in Joules...

Homework Statement What direct current will produce the same amount of thermal energy, in a particular resistor, as an alternating current that has a maximum value of 2.60 A? Homework Equations The Attempt at a Solution A DC would dissipate a constant amount of thermal energy in a...

Homework Statement A 1200kg car skids with uk = 0.45. If it skids 45.2m, find the thermal energy and the initial speed. m = 1200 kg Vi = ? Vf = 0 m/s (i think..because it wants to stop) uk = 0.45 (coefficient of friction) delta d = 45.2m Homework Equations Well for Frictional...

Q: 20 J of heat energy is added to an ideal gas while -40J of work is done BY the same gas. The total change in internal thermal energy of the system is what? Equations I used: \DeltaEth = Heat + Work \DeltaEth = Heat - Ws This was a problem on a recent physics test I took and I said...

Homework Statement Two railroad cars, each of mass 7650 kg and traveling 95 km/h in opposite directions, collide head-on and come to rest. How much thermal energy is produced in this collision?Homework Equations I'm assuming: KE=1/2mv^2 HE=mc(delta)TThe Attempt at a Solution The answer is...