At the end, you can pretty much say radiation is to be neglected. 11) Burning your hand on a hot pan Ice cubes keeping lemonade cold. Flashcards. The toast is also touching some type of metal grate that gets hot, and thus that contact is conduction. Which material(s) keep the ice cube from melting the longest? It is defined for a continuum, a solid material, but can be thought of as heat passed on between neighbour particles. Steam piping out of a teapot. So we can ignore forced convection. Radiation. b) If N1N \gg 1N1, use the information given in Appendix BBB to show that II0(12/4N)I \cong I_0\left(1-\pi^2 / 4 N\right)II0(12/4N). Forced usually involves some kind of forced movement of the fluid over a surface. Conduction Convection Or Radiation Worksheet When you mention Brownian motion, it is relevant here with conduction: The random motion of particles, electrons etc. These lemonade ice cubes will keep your glasses chilled, but not watered down as they begin to melt! No no, it doesn't rule it out. A cup of cold water will also eventually reach room temperature. endstream endobj startxref MathJax reference. 34-35, Thinking Physics, 3rd edition), Finding the terminal velocity of a model rocket from a list of velocities. For thin fluids (with low viscosity), the convective effect of effective heating/cooling due to fluid motion is dominant. Water from a reservoir is raised in a vertical tube of internal diameter D = 30 cm under the influence of the pulling force F of a piston. hb```a``t lF0F (f`(`b`1Ql"@ / The solid ice in this case stays pinned at one temperature as it completely melts. Forced convection, which is fluid flow caused by non-natural mechanisms such as by a pump. We end up with only convection (natural in your case) having a large influence in your case - in fluids, this is often the only effect that is relevant to consider, unless when sinking a glowing-hot metal into a very volatile liquid. The areas wont line up, obviously, so you'd have to do some conversions, but we're talking 5 orders of magnitude weaker than the sun. Z(6GF- F? Conduction Convection Radiation | Science Quiz - Quizizz Q. Tongue freezing to a metal pole. 1) 2) Warming hand over a radiator. What "benchmarks" means in "what are benchmarks for?". 22. $4%&'()*56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz ? Convection. Give your result in miles per hour. It follows Stefan-Boltzmann's law: $$\dot q_\text{rad}=\varepsilon\sigma_sA(T_1^4-T_2^4)$$ ($\dot q$ is energy per second transferred from body 1 to body 2, $T$ temperature, $\varepsilon$ emissivity, $\sigma$ the Stefan-Boltzmann constant, $A$ the radiating surface area. Fusion is endothermic. An insulating material such as cotton balls, bubble wrap, crumpled paper, and so on (more than one is optional)enough to mostly fill one of your large food containers. Plus, the heating element is hot enough to quickly burn the toast - if the toast were touching the elements, it would have lines on it as if it were sitting on a grill. It just so happens 1 form is dominant (i.e. In pure materials (water), fusion occurs at a constant temperature. Of this reason you will never hear conduction described for atomic particles; which is why it doesn't make much sense in your scenario either. *Z(6AA LQKE &A)h m - Gh= :Z(Giv@ {tm - GF@ FKE &E- QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE QE J:( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( Bqi `>\P$B2c8qS|% \g9 )A$~Go\\>o_Z u5=}{{]XeNFHphSK&8{zPy#Hps= >hu=oCF/r RgdPI{T9= q@QQn }qJeQE3^8n {PeQ {Py>l{uOj }1ys@dPwp 5D[~~Cj pCd~$W$a3 Twp IE1 `xRz}):Uv(Z*6T1!\= At the end, we have conduction. In this case heat flows from the hot drink to the cooler environment. Conduction. Quickly close the lid on the "insulated" cooler container. Radiation is a 4th power effect, so that means the effects will be 20^4 less. Ice cubes keeping lemonade cold. But the hot coils touch the toast so an element of heating by conduction occurs as well. While you are right that convection and the sound barrier do not exist in the most strict of technical senses, I just wanted to make sure somebody doesn't get the wrong idea from the words. hUmo0+}n@"tY"jP[-J)mUM{{~(H %PDF-1.5 This is counterintuitive (for many students) because metals feel cold while plastics feel warm. This is because the heat from the water, which is warmer, flows to the ice cube until both are at the same temperature, and therefore no ice cube is left. Thanks for contributing an answer to Physics Stack Exchange! For the heating elements of a toaster to reach optimal temperature they CANNOT touch the toast. Q. Roasting marsh- mallows over a fire. Conduction is correct because like a saucepan, the flame is touching the toast and heating it one layer at a time. Place one ice cube in each of your smaller containers or bags. How big is the ice cube in the open container now? Tongue freezing to to a metal pole. More accurately, it is the transfer of wavelengths on the spectrum of light that when absorbed by the body is converted into heat). {yum!} Two plastic food storage containers. hbbd`b`rdb`cb`l@z&&F9L ?D Target: Classify heat transfer as conduction, convection or radiation. Liquid water does not support free electrons (of course not!) Convection occurs when a fluid (such as air or water) flows over an object. It is the second law of thermodynamics at play. Try the activity again, but tightly pack the insulation against the walls to leave more room in the container. 13) Laying out in 14) the sun. You can find this page online at: https://www.sciencebuddies.org/stem-activities/build-a-cooler. warming your hands over a . Lemonade Cubes: The Secret to Perfect Lemonade! - The Frugal Girls Learn. How to Make a Black glass pass light through it? Conduction, Convection, and Radiation: An Introduction Convection is an important and dominant mechanism to maintain the liquid layers close to the ice surface at higher temperature. %%EOF Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. What You'll Do: Simply pour your Fresh Squeezed Lemonade made from the recipe below into an ice cube tray and freeze. Energy transformation questions & answers for quizzes and tests - Quizizz %PDF-1.3 % . joules. , Test. Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. in a toaster). This observation would exclude the possibility that the melting process in the present case could start in the bulk of the ice. A Probability STEM activity. Best Heat and Energy Flashcards | Quizlet endobj edit: Also, what do you mean by "the flame is essentialy a liquid"? nor does it support lattice vibrations (that is what is happening in the ice). In a sense -- all 3 forms of heating are involved in cooking no matter what. One of the containers is otherwise empty, and one is lined with cotton balls. It is kind of artificial as in the molecular level the difference is small but at the macroscopic level, the differences emerge. You feel conduction when you touch, for example, an ice cube or a hot mug. The temperatures of the solid ice and liquid water control the net radiation flux. When the objects reach the same . 2 0 obj The key is insulation! Some propane has a density of 48.5oz/ft348.5 \mathrm{~oz} / \mathrm{ft}^348.5oz/ft3 at 265psi265 \mathrm{~psi}265psi gauge pressure. Q. Warming hand over a radiator. _q|A=h\M)U:zH?E#oa\>?,yG^Q?:E;6gxq\#tL#sIdZ>R&?k(FQd-fE%gy$[;}tnOO6nP. conduction. You feel convection when you stand outside in a chilly winter wind and feel cold. A reference graph showing the variations in conductivity is found at this link. Thus, natural convection can be a factor in the heat flow. 1 pt. A circular flow of warmer fluid nad cooler fluid is called ____________________, Heat is always transferred from ___________ areas. How cold does this ice have to be to freeze this water bottle solid? Energy is transferred by heating from the hot coffee to the cold surroundings. Those "hotter" liquid water molecules are colliding constantly with those "colder" solid ice molecules (hot and cold as measures of internal energy). The energy arrives as heat from the surroundings. Or how can you at least slow it down so your food doesn't spoil? $F^Nr3{PTx%P x'-)(|zrG. You can feel the warmth of the sun on your skineven though the sun is millions of miles away with the vacuum of space between you and it (so there is no matter that allows for conduction or convection)! Conduction, Convection, Radiation Flashcards | Quizlet the melting of a solid starting from the surface layers, instead of than from the bulk, is a phenomenon present even in the case of ice. 1) 2) Warming hand over Eggs cooking in a radiator. 1) 2) Warming hand over Eggs cooking in a radiator. in a kettle. Conduction occurs when objects are in direct contact with one another. Think also about a cold penny that sits inserted into an insulated floor with hot air above it. There are three different ways heat can move between objects: conduction, convection and radiation. Making statements based on opinion; back them up with references or personal experience. When printing this document, you may NOT modify it in any way. JFIF C 2!=,.$2I@LKG@FEPZsbPUmVEFdemw{N`}s~| C;!! If commutes with all generators, then Casimir operator? How do you stop heat transfer if it's happening naturally all the time? radiation. Do you know what a shear stress is? Created by. Currently I have two answers: Infrared radiation from the water transfers thermal energy to the ice cube, which increases the ice cube particles KE store, breaking the intermolecular bonds of the ice cube, melting it. h2T0P(ON-pqMLOuOJM.J{*@ Does liquid water remain at thermal equilibrium with ice at the melting point of ice? Answer the following question to test your understanding of the preceding section: This analysis can be verified by looking up numbers, as some comments ask for, of water and ice for the different models as well by comparing with the viscosity. How does ice melt when immersed in water? In your case we have natural convection: The water particles near the ice surface deliver heat to the ice and in turn cool down. If your insulation is opaque, it also reduces the amount of heat transferred by radiationalthough this is a much bigger factor outside in the sun than if you're doing the activity indoors. Write a short paragraph that explains why the phosphorus cycle occurs slower than the carbon and nitrogen cycles. If they touch the toast conduction will carry way the heat to fast for the element to get hot. Inversely, you might find that when you mistakenly think the ice gets hotter during melting, you will immediately have to shut down any and all net heat transfer from the surroundings (liquid) to the system (ice). )bBL%f33gVblWiF 2 0 s endstream endobj 13 0 obj <> endobj 14 0 obj <> endobj 15 0 obj <>stream To speed up the activity put your containers in the sun and/or take them outside on a warm day. Why do you think that is? Match. The three forms of heat transfer between a system and the surroundings are as follows: This is the transport of heat by particles exchanging their internal energy. When the temperature of an object increases, the particles that compose the object begin to move faster. A reasonable one-particle description of the atomic dynamics in dense liquids is a kind of superposition between diffusion and the so called cage motion which is the analogous of atomic vibration in a solid. 7) 8) Newt boiling in Ice meltinga hot caldron. If you need to keep something cold for a long time, would you use a lightweight, thin-walled cooler or a cooler with thicker walls? 18 0 obj <>/Filter/FlateDecode/ID[<4F69E78F45578AADA7A87719597465F7><934D015383B054419E748442011DBB42>]/Index[12 9]/Info 11 0 R/Length 44/Prev 398603/Root 13 0 R/Size 21/Type/XRef/W[1 2 0]>>stream What would your response be for h = 3 m? Learn more about Stack Overflow the company, and our products. What exactly does the cooler do that's so special? Find the gauge pressure when the density is 30.6oz/ft330.6 \mathrm{~oz} / \mathrm{ft}^330.6oz/ft3 . You may print and distribute up to 200 copies of this document annually, at no charge, for personal and classroom educational use. Water boiling in a kettle. Other materials can block radiation in visible or infrared light. Does this change how quickly the ice cube melts? Does a crushed ice cube and a regular ice cube have different potential energies? Does an ice cube change its core temperature as it melts? This is the transport of energy from an object as electromagnetic radiation. Heating gasses in space -- How could we make a greenhouse in space? . This is how thermal energy is conductively transferred. 0 That's 160,000 times less than the effect of the sun. (direct contact), fluids-liquids and gases transfer heat through currents, the movement of atoms and molecules (thermal energy), 1. Conduction Convection Radiation | Other Quiz - Quizizz These now "colder" water particles are denser or "heavier" and will sink. Two equally sized plastic food storage containers (one will need to have a tight-fitting lid). Hence show that if NNN is very large, the final intensity is essentially the same as the initial intensity. Ice cubes keeping lemonade cold. It occurs in one of two modes -- free or forced. 10) Steam piping out of a teapot. Some may have two possible answers. Heat, insulation, Mostly fill the inside of one of your plastic containers with insulating material. ?cn KEDgA"O9v?tT%g$FON_'{1e 5) 6) Warmth from the Tongue freezing to fireplace circulating to a metal pole. If the cube and water together form an isolated system (no heat transfer between them and their surroundings) the heat transfer will continue until all the ice is melted, or until the water temperature equals 0 C at which point any ice remaining will be in two phase thermal equilibrium with the water. To melt, atoms in a solid must gain enough energy to leave their bonds in the solid. Water boiling in in a kettle. endstream endobj 13 0 obj <> endobj 14 0 obj <> endobj 15 0 obj <>stream This same thought is behind the formation of cold and hot fronts with thunderstorms in weather patterns. To Hootenanny: Conduction is generally most important in solids, but it also occurs in liquids and gases. 1. Warmth from the fireplace circulating through the house. liquid-gas, change of state: what takes place? It's good to classify the different forms of heating that can occur. roasting marshmallows over a fire. Eggs cooking in a frying pan. What does 'They're at four. radiation. Heating a kettle on a hot furnace. Learn. endobj When the ice cube in your open container finally melted, you might have discovered that the ice cube in the insulated container was still almost half its original size! Ice melting on a hotplate. Conduction occurs when objects are in direct contact with one another. You can observe this by watching (and feeling) a hot drink. That's a lot of different ways for heat to flow from one place to another. Describing transport of energy in a liquid in term of collision is as good or as bad as using the same explanation for conduction in solids. How do the general effects of the sympathetic division differ from those of the parasympathetic division? ), Thermal conduction transfers heat through a solid. I've modified my description to account for your insights in a manner that keeps it simple without I distorting the truth I hope. Can you optimize this design with different materials. Solid-liquid, change of state: what takes place? Oe^4wv How long does it take the sun to melt an ice cube? Some materials are poor conductors of heat so they make good insulators to slow down heat conduction. Are they both equally as valid or is one more valid than the other. Has it also fully melted? This causes the coffee to cool down. When the liquid is only infinitesimally above the ice in temperature, the net radiation flux is small. Conduction requires (or sets up) a temperature gradient in the material that is transporting the heat. But, as you can see, convection is basically a "flow-version" of conduction if we consider it microscopically. There are three different ways heat can move between objects: conduction, convection and radiation. ;|SFS|||||||||||||||||||||||||||||||||||||||||||||||||| " The Brownian motion of the water particles causes them to collide with the ice cube, transferring KE to the ice cubes particles, increasing temperature, breaking intermolecular bonds and melting it. Use MathJax to format equations. We use cookies and those of third party providers to deliver the best possible web experience and to compile statistics. It is a well established observation that pre-melting, i.e. liquid-solid, change of state: what takes place? PDF Heat Transfer Review - Coach Mundok'S High School Physical Science Can you give an estimate about the ratio of infrared? "[I@ |9,{ ,brHI (;D\&ELoX&gH? PS endstream endobj startxref 0 %%EOF 55 0 obj <>stream Convection cennot play a direct role. I will not do this in this answer, but it should be fairly easy to find online; other answers are giving some of such numbers to justify the conclusion. In general, there exist three heat transfer mechanisms: Thermal radiation transfers heat across a distance. If you had a stagnant liquid with a negligible thermal coefficient of expansion (e.g. Q. Conduction. 9I5 3nq#m[B`8zm @pentane There are two kinds of convection: forced and natural. Radiation only requires that objects have a temperature. It follows Fourier's law: $$\dot q_\text{cond}=A\kappa\frac{\Delta T}{\Delta x}$$ ($A$ is area through which the heat flows, $\kappa$ thermal conductivity, $\Delta T$ temperature difference between two points, $\Delta x$ distance between those two points over which the heat is tranferred.). Go do something else for 15 minutes, and then come back. __________________ is the transfer of energy by electromagnetic waves. Single-digit percent? For any other use, please contact Science Buddies. Also, taking the atmospheric pressure to be 96 kPa, plot the absolute water pressure at the piston face as h varies from 0 to 3 m. The polarization direction of linearly polarized light must be rotated by 9090^{\circ}90. To learn more, see our tips on writing great answers. But this doesnt fit the formula you gave where. Radiation 2. For a better experience, please enable JavaScript in your browser before proceeding. Example 2 - drinking a hot coffee on a cold day. Determine the force needed to raise the water to a height of h = 1.5 m above the free surface. %PDF-1.4 % The above three energy transfer factors are all the possibilities there are to transport energy. As soon as that ice cube finishes melting, open your cooler and check on that ice cube. Convection. 1 0 obj Match. Finally, heat can be transferred by electromagnetic radiation. Adding EV Charger (100A) in secondary panel (100A) fed off main (200A). Energy Worksheet 2 - Whitnall High School - YUMPU cause them to "bump into" and interact with neighbour particles. Place a zip-top bag or smaller plastic container inside each of the larger containers (make sure that the lid on the insulated container will be able to close all of the way; remove any insulation needed until the lid can close; leave it open for now). Ice cubes keeping lemonade cold. Saying the ice is surrounding by water and mixed with it will lower its contribution. 10) 12) 14) 16) Steam piping out of a teapot. the transfer of thermal energy from one particle of matter to another. answer choices Conduction Convection Radiation Tags: Question 10 SURVEY 30 seconds Report an issue Q. Overall though, it is mostly radiation. Don't forget about convection in the case of the toaster. 3) 4) Snowman melting in the sun. on a hotplate. 9) Freezing outside on a cold day. endstream endobj 17 0 obj <>stream If so, the particles(and the bodies)must be touching so there should not be any distance between the two points. When you say radiation, are you referring to infrared radiation? What's the cheapest way to buy out a sibling's share of our parents house if I have no cash and want to pay less than the appraised value? on a hotplate. Each contains a smaller plastic cup with an ice cube inside. GDV, If not, how big is it? Did the drapes in old theatres actually say "ASBESTOS" on them? The penny will have no natural convection modes because the cold air that might form around it is already denser than the hot air above it. Natural convection, when it occurs, swamps conduction heat transfer (well, not literally of course). 3) 4) Snowman melting Water boiling in in the sun. Conduction, Convection, Radiation Flashcards | Quizlet Are there any canonical examples of the Prime Directive being broken that aren't shown on screen? Thermal radiation could still be a factor as well, but at fairly low temperatures, radiation is low (note the power of 4 in the model) and possibly negligible. If the latter than which one and by how much? In this case heat flows from the warmer environment to the cooler cup. If your workspace isn't very warm, the ice cubes might take a while to melt. a frying pan. %&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz Q. Which ice cube do you think will last the longest? Does this rule out the first answer I gave? Laying out in the sun 2. thermal energy. the total kinetic and potential energyof all the particles of an object. This is the transport of heat content by the bulk motion of a fluid over an object. Ice melting on a hotplate. Opening this jar is made easier by cooling or heating? Roasting marsh- mallows over a fire. You feel conduction when you touch, for example, an ice cube or a hot mug. Conduction Convection Radiation Worksheet CW from studylib.net 11) 12) burning your hand ice cubes keeping on a hot pan lemonade cold. It only takes a minute to sign up. What is Wario dropping at the end of Super Mario Land 2 and why? Radiation because the flame is emitting electromagnetic waves in the form of infrared as the temperture is quite high. 2) liquid: moving around, have definite volume PDF TEACHER BACKGROUND: SPECIFICS OF HEAT TRANSFER - National Oceanic and Ice cubes (at least two of the same size), Two plastic zip-top bags or matching smaller food storage containers/cups that fit inside the larger ones. Therefore we are left with conduction or radiation as possible ways to tranfer thermal energy from liquid water to the ice. Conduction. What is this brick with a round back and a stud on the side used for? Post your question for our scientists. Q. Snowman melting in the sun. Sure the coils heat the air near them too, so the air gets some movement to it and thus some converction is taking place. They are generally considered on equal terms as three distinct mechanisms with each their own energy transfer models. YuB/8#J'XWM3 Tp*{/P8at-o |J@m~cZz. 12 0 obj <> endobj 38 0 obj <>/Filter/FlateDecode/ID[<0BDB4745D53B1A57384DF0991911DC71>]/Index[12 44]/Info 11 0 R/Length 108/Prev 917909/Root 13 0 R/Size 56/Type/XRef/W[1 3 1]>>stream In general, natural convection is the mechanism behind hot air rising and cold air falling and similar phenomena.). To understand what happened in this project, you need to learn a little bit about heat transfer. Increasing the temperature causes an increase in the particle speed. I have added an explicit statement at the beginning of the third paragraph. "Signpost" puzzle from Tatham's collection. 7) 8) Newt boiling in Ice melting a hot caldron. the particles in solid objects touch eachother and transfer. . Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Thermal conduction is not really defined for particle-to-particle. My point was about modeling the atomic dynamics of a liquid as collisions. If you have an object that's around 300K, that's 20 lower temperatures. The ice is radiating from it. They either vibrate more rapidly, rotate with greater frequency or move through space with a greater speed. Depending on how fast it is melting, continue to check the ice cube periodically. Conduction convection radiation interactive and downloadable worksheets. Q. Newt boiling in a hot caldron. Can heating via Microwave oscillation be specific to a single molecule? An additional remark could be added on the microscopic description of the melting process. Answer the following question to test your understanding of the preceding section: Describe some reasons for the declining efficiency of the immune system in old age. Test. % the transfer of thermal energy from a warmer object to a cooler object. Sorry, the flame is 'fluid', careless error on my part. Multiple-choice. What should I follow, if two altimeters show different altitudes? Try making multiple coolers with different insulating materialsor even combine layers of multiple insulating materials inside a single cooler. It would probably be nice if you had room for food and drinks in your coolerinstead of filling it mostly with insulation. heat. If so-does the transfer of KE by water particles colliding with the ice cube come into the picture at all? A flame does deform to some extent uder an applied shear stress but not a lot. Why does Acts not mention the deaths of Peter and Paul? where's the flow? Heat is transferred directly from one particle of matter to another by the process of ? Convection requires a temperature difference. Radiation. @CortAmmon Thanks, this was the kind of estimate I had in mind -- I missed the 4th power in the Boltzmann equation. A work surface where both of your containers will have equal exposure to external sources of heat (such as sunlight or a vent). Say, by way of a fan, the wind, a pump for water, etc. Add to this that both ice and water have emissivities well below unity and their emissivities are comparable. Warmth from a fire place CIRCULATING through the house, the transfer of energy between the particles of two objects where one has a higher temperature than the other, a substance which promotes the flow of heat or electricity, something that blocks the flow of heat or electricity, Exam 1- advanced investigation techniques. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 4 0 obj Try blowing on a flame and see how much it deforms 2023 Physics Forums, All Rights Reserved, http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatra.html#c2), Thermodynamics of Resistive Heating at Low Power, Question: To use or not to use? The key point motivating my comment is that neither diffusion nor cage vibrations can be reasonably modeled as simple collisions. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Convection 3. However, there's a key point where the momentum of the gas particles becomes substantially more anisotropic (starts to have a direction), and when that happens we see shock waves anda "sound barrier.". For very thick fluids (with very high viscosity), so thick that you might mistake them for solids, heat can flow from particle to particle in a conductive manner, and conduction is dominant. Ice cubes are placed on metal and plastic blocks; the cube placed on metal melts much more quickly than the cube placed on plastic. In your case with water that has a rather low $\kappa$, we should be able to assume only a predominantly convective mechanism and no/negligible conduction over longer distances in the water.