Moreno, Maricon Garcia 10 December 2009

Moreno, Maricon Garcia 10 December 2009

Sir Raymund Bolalin Take Home Examination

1. The Sun and Earth is not in thermal equilibrium because the Earth is a sphere. This means that it heats equatorial regions more that polar regions. Furthermore, the atmosphere and the ocean work to even out solar heating imbalances, this happens through evaporation of the surface water, convection, rainfall, winds, and ocean circulation. The climate’s engine must not redistribute heat from the equator towards the poles, and also from the Earth’s surface and lower atmosphere back to space. If this does not happen, the Earth will heat up endlessly. Source: http://earthobservatory.nasa.gov/Features/EnergyBalance/ 2. Yes, the argument makes sense. It is indeed energy saving when you follow the advice.

It is similar with a heater. A heater would consume more energy if you turn it off and then turn it on since it requires generating more energy to produce hot water. Unlike when you just leave it on, it wouldn’t have a hard time to again produce hot water. Rooms are kept an a constant temperature so that it would not require to use more energy to cool it down by an air-conditioner, for example, that will use up energy to produce cold air. An automatic air-conditioner that can control the room temperature, you would notice that if the temperature of the room before turning it on, the airconditioner would produce loud sound which indicate that it is consuming more energy. When it comes to the point that the room temperature is constant already, you will notice that the sound that the air-conditioner will produce will change from loud to close to silent. 3. Energy flows into our body from different sources such as energy from surrounding air, surrounding objects, and from the sun when you are outdoor The type of energy transfer from one place to another is heat flow. Heat transfer is a process by which internal energy from one body is transferred to another body. There are many ways that heat is transferred. These are: Conduction is when heat flows through a heated solid; Convection is when heated particles transfer heat to another substance, such as cooking something in boiling water; Radiation is when heat is transferred through electromagnetic waves, such as from the sun. Radiation can transfer heat through empty space, while the other two methods require some form of matter-onmatter contact for the transfer. This only means that even though it is not right to say that a body contains certain heat energy, there are many factors that may affect it through different ways of heat energy transfer. The surroundings of a certain body will transfer heat energy to it also that certain boy can transfer it no another body or substance. Heat energy is present everywhere so it is easy to be transferred from one body to another. There are many factors that can easily affect the thermal energy of one substance and pass it to another.

This type of energy transfer id calle heat flow. It is a process which internal energy from one body to another is transferred. 4. Opening the fridge door, warms the air in the fridge slightly. As a result, the temperature

monitor finds that it is too warm, so it attempts to cool it down. BUT to cool the fridge down, the fridge needs energy (electrical energy) and when the electricity is converted into the cooling energy, heat energy is released at the back of your fridge - that's why the back of your fridge is often very hot (if you touch it). So opening your fridge increases the amount of heat energy released at the back of the fridge. This heat energy released at the back of your fridge would probably heat the room up faster than the cool energy would cool the room down Because, refrigerators do not produce cold. The system is like that of an air-conditioner. The freon in the cooling lines absorbs the heat and is then pumped to the back of the refrigerator where the heat dissipates into the surrounding air and the freon is pumped back into the refrigerator to repeat the task again. So, any heat removed from the air would just be released into the air on the other side of the fridge. that is why the heat dissipation side of air conditioners is outside. The cooler full of ice will cool the air until the contents of the cooler reach room temperature again. 5. Weight: 28.4N Heat Energy: 1.25 x 104 J Change in Temperature: 18.00 C Specific Heat of the Metal: 57.2kJ H=mc(change in temperature) 2987.572 Cal=(28.4Nx9.8m/s2)c(18.00 C) c= 2987.572/52.2 c= 57.2kJ