Thermal energy Definition and 199 Threads

This question appeared in my IB Physics HL mock exam and I am stumped by the answer on the mark sheet. It really should be a trivial question but it's open to interpretation which is why I find it unreasonable. It was in Paper 1 from November 2014, 1. Homework Statement ? Which of the following...

Homework Statement Wet clothing at 0°C is hung out to dry when the air temperature is 0°C and there is a dry wind blowing. After some time, it is found that some of the water has evaporated and the remainder has frozen. Estimate the fraction of the water originally present in the clothing which...

It seems possible to extract energy from the ambient air without temperature gradients (or at least with very small local gradients that will always be available). Being curious about this, I checked out some other threads and did not really find the specific question. (I did find some...

What I understood so far is that whole universe was born from a single point at which there was no time (or all the time was at single point - no present, no future) and then a big bang happened (may be), creating time, energy, mass etc. I want to learn physics at much deeper levels. So, I...

So I live in Florida and I don't use my air conditioner, so my apartment gets pretty hot sometimes. It occasionally gets over 90 degrees F. I had an idea of how to cool the room, but I'm not sure how feasible it is. My idea is a device that could turn that thermal energy into work, which should...

Homework Statement Homework Equations Q = c m ΔT The Attempt at a Solution so converting 55 mph to meters per sec gives me a velocity of 24.58 m/s kinetic energy of car is 1/2 m v2 i set 1/2 m v2 = c m ΔT plugging in v and c and masses of both ΔT = 134.56 is that correct?

I know that temperature is used to measure the average internal kinetic energy of an object, but how do we go about measuring thermal energy? It seems as though temperature could only compare the thermal energy of objects with the same mass and volume. But for objects with different mass and...

Homework Statement A jeweler heats 25g of pure gold until molten. If the initial temperature of the gold is 22 degrees celcius, calculate the amount of energy required for the process. Homework Equations c = 129 Lf= 64 500 Lv = 1578000 Tmelt = 1064 The Attempt at a Solution Q = mct =...

I am little confused as to why temperature is a measure of thermal energy. Thermal energy is defined as the total internal kinetic energy of an object. Temperature, on the other hand, is defined as the measure of the average kinetic energy of an object, or the thermal energy per particle. If...

Homework Statement Interstellar medium is composed of atomic hydrogen at 100 K and number density 2E-7 m-3. Compute the average thermal energy density of the milky way disk. Then find the average magnetic energy density given the magnetic field strength of 3E-10 T. Homework Equations E=3/2 kT...

Homework Statement A block of mass M is pulled at constant speed with force F a distance d across a surface. Using the energy principle, what can you say about the change in thermal energy of the block? a)...

Homework Statement A hair dryer consists of a coil that warms air and a fan that blows the warm air out. The coil generates thermal energy at a rate of 600 W. Take the density of the air to be 1.25 Kg/m^3 and its specific heat capacity to be 990J/Kgk. The dryer takes air from a room at 20C and...

MODERATOR NOTE: MISPLACED HOMEWORK, SO NO TEMPLATE When filling up the tub for a bath, only the hot water tap was turned on. After realizing the mistake after a minute with half the tub at 60 C, how much cold water (as fraction of the whole tub) at 9 C must be added such that the final...

Homework Statement a) Assume that a substance in a closed container is at thermal equilibrium with about half of its molecules in the gas phase and half of its molecules in the liquid phase. How could you use the Particle Model of Thermal Energy to explain which molecules are moving faster, on...

Homework Statement Hello, I have the following problem (an ABCD question): Two objects near each other are at the same temperature. Which of the following statements has to be true? A. The objects have the same internal energy. B. The objects have the same thermal capacity. C. No...

Recently there was an interesting thread on physics forum about possible uses of spent nuclear fuel. It seems to me that one of the problems with using decay heath from spent nuclear fuel is the low power density. This got me thinking that maybe with enough insulation the low quality heat...

hello is there a good article or reference to outline the available methods to harvest ambient or solid thermal energy and their efficiency and limitations? thanks!

I am trying to figure out what the total thermal energy emitted by completely transparent matter. It seems Planck's law can't do this because the thickness or geometry of the mass is not given, only it's surface area. The spectral radiance of a black body is given by Planck's law...

A microtubule is 100 microns long. Take the young modulus as 1 GPa and the microtubule as a hollow cylinder with outer diameter of 12.5 nm and thickness 2.5nm. a) If one end of the microtubule is clamped down, and is the other end is free to wobble. Estimate the work that must be done to...

Homework Statement A spherical air bubble in a lake expands as it rises slowly to the surface. At the point it starts to rise, the pressure is 2.00 atm, the temperature of the water is 10.0 ∘C, and the radius of the bubble is 5.00 × 10^−3 m. At the surface, the pressure is 1.00 atm and the...

The fastest way to transfer thermal energy would be through: A. Thermal radiation B. Thermal conduction C. Thermal convection D. Thermal induction I thought it would be thermal radiation, but my teacher said its conduction. Is he right? Please explain.

Homework Statement [/B] Suppose the main water pipe breaks in a nuclear power plant, shutting off the water flow. If the control rods fall immediately into place, stopping the chain reaction, is there still a problem? Yes, because radioactivity continues to create lots of thermal energy. (A)...

Homework Statement A block with mass m = 1.46 kg is attached to a spring with spring constant k = 52.0 N/m and negligible mass. The coefficient of kinetic friction between the block and the table is µk = 0.349. The block is displaced from its equilibrium position to the left by 0.203 m...

Homework Statement During a rockslide, a 710 kg rock slides from rest down a hillside that is 500 m long and 300 m high. The coefficient of kinetic friction between the rock and the hill surface is 0.23...

Homework Statement Suppose a car approaches a hill and has an initial speed of 116 km/h at the bottom of the hill. The driver takes her foot off of the gas pedal and allows the car to coast up the hill. Randomized Variablesvi = 116 km/h m = 780 kg h = 20.5 m a = 2.3 ° Part (a) If the car has...

What is the relationship between heat and thermal energy?

Hi everybody, I hope this is the appropriate place to post this question: A middle school physics book here in Sweden poses this question after giving a brief explanation of E = mc2: For you Swedish speakers here is the original text: So my answer is "Yes" to both since the additional...

I want to calculate the energy applied to a slab of steel with a temperature rise that varying with time (t) as - 13t + 5t^2 + 10* sin (3ωt) The energy applied to the system is calculated by mc (dT) equation where m mass of the slab c specific heat dT change in temperature

im not talking about geothermal energy because my teacher gave us topics and mine is thermal energy and i did some research but i still don't get it if its renewable or nonrenewable because i got mixed answers when i researched about it. and are there any advantages for this energy? i think...

Thermal energy is momentum right? Is this a correct interpretation: If I slide an object across a frictional surface, the momentum will still be conserved, just not visibly (because it's now atomic momentum, called "thermal energy"). If yes, then, in all of these conservation of momentum...

I have to calculate the amount of thermal energy due to friction, it will be rolling friction if that makes a difference but i would like to know how (if possible) to calculate thermal energy due to friction in sliding friction as well. Thank you!

Homework Statement How much thermal energy was in 1 cubic meter of air at room temperature. Give your answer in Joules. How much kinetic energy does one cubic meter of air have if it were to hit the ground after falling 100 m? Give your answer in Joules. Which has more energy...

1. A 0.25kg piece of ice at -30°C is warmed by an electric heater and the following graph of the temperature is produced (I just redrew the graph). Assume that there has been no loss of energy to the surroundings. a) use the information on the graph to determine the power output of the heater...

Using a heat source to increase the temperature of an agricultural commodity like corn, could a thermal camera detect temperature differentials over time as the commodity cools, versus localized surface contaminants such as mold or fungus? I'm thinking yes in theory but the differences might be...

Homework Statement How much work is done on the gas in the process shown in figure P12.24. This is from College Physics: A strategic approach, 2nd addition, by Knight, et al. Ch.12, #24 The graph shown is kPa vs V(cm^3). It's a constant temperature process (isobaric) at 200 kpa. I was able to...

Homework Statement 160 grams of boiling water (temperature 100° C, heat capacity 4.2 J/gram/K) are poured into an aluminum pan whose mass is 950 grams and initial temperature 26° C (the heat capacity of aluminum is 0.9 J/gram/K). (a) After a short time, what is the temperature of the water...

Homework Statement Starting from rest, a railroad car rolls down a hill 20 m high and hits another identical car at rest. The cars lock together after the collision. What fraction of the first car's change in potential energy is converted into thermal energy in the collision?Homework Equations...

The thermal energy comes from the translational kinetic energy right? The relationship between the two being E(kin)=1.5kT how would i go about finding the total thermal energy of a system of a given volume and pressure?

question:Calculate the total thermal energy in a liter of helium at room temperature and atmospheric pressure. Then repeat the calculation for a liter of air. I'm just confused because i thought thermal energy only depended on the translational kinetic energy of the particles. So why do i...

Homework Statement A silver block, initially at 58.5* C is submerged into 100.0 g of water at 24.8* C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.2* C. What is the mass of the silver block? Homework Equations q = M x Cs x Δ T 1/M...

Hey guys. From my understanding, Temperature is a measure of the average kinetic energy of the molecules within a substance. Heat is the transfer of thermal energy between a system and its surroundings Internal Energy is the total energy (kinetic + potential) of the molecules of a...

A potential difference of 50 mV is maintained between the ends of a 9.70 m length of wire whose cross section area is 25.0mm^2. The conductivity of the wire is 6.80 x 10^6 (ohm.m)^-1. Determine the rate at which the energy in the wire is transformed into kinetic to thermal energy. 2. Homework...

chem12 Thermodynamics -- thermal energy question Homework Statement Which would have a higher amount of thermal energy: cup of tea @ 75°C OR bathtub of water @ 50°C Homework Equations q=mcΔT The Attempt at a Solution I know both are made of water with a specific heat...

Task: A steady flow boiler takes in feed water at 1.5kg/s, at a temperature of 30 °C. The water is heated and turned into wet steam. This leaves at 1.5kg/s, with a pressure of 10 bar and a dryness fraction of 0.97 to the superheater, where it receives heat at a constant pressure and emerges...

Identify the incorrect statemet from the following: A) The thermal energy of an object is the sum total of the kinetic energy of random motions of all its atoms/molecules. B) Heat is the flow of thermal energy. C) Temperature is a measure of the average kinetic energy of random...

A worker pushed a 23 kg block 13 m along a level floor at constant speed with a force directed 22° below the horizontal. If the coefficient of kinetic friction between block and floor was 0.40, what were (a) the work done by the worker's force and (b) the increase in thermal energy of the...

Homework Statement For science fair, I'm doing a project in which we are trying to calculate the force of a thermometer being moved normally, versus a thermometer being slowed down by a high-friction material. The thermometer will (Potentially) read the amount of thermal energy produced by...

Hello all.. I know this thread is asked a lot before and i read some of them.. but to make sure that i understand and to make like a small resume can we say: Heat is the "quantity" of the thermal energy being exchanged? i mean its like the work that is responsible for the change of the kinematic...

Homework Statement Compute the change in internal energy, ΔU, and the final temperature, Tf, when 1 mole of an ideal, diatomic gas is compressed adiabatically to 89.700% of its initial volume. The starting point is 22.500°C and 16.100 L. (Assume that the vibrational degree of freedom stays...

Hi guys. I was wondering, what happens to the temperature of a object if it's put into vacuum? Say you have a box of steal (something that transfers thermal energy fast between the inside and outside). Inside the box you have a rock. The rock is held in the center of the box using...