Self+Check-

=__**Self Check**__=


 * 1) **Explain how energy moves when you touch a block of ice with your hand.** //~ Thermal energy transfers from you hand to the block of ice.//
 * 2) **Describe how the thermal energy of an objict changes when the object's temperature changes.** //~Temperature is related to kinetic energy so when the kinetic energy changes thermal energy chnges also.//
 * 3) **Infer when heat flows between two objects, does the temperature increase of one object always equals the temperature decrease of the other object? Explain.** //~ No. Temperature change depends on the specific heat of each material//**.**
 * 4) **Explain why the specific heat of water is higher than the specific heat of most other substances.** //~Molecules of water have strong bonds between them that require energy to break before an increase can occur.//
 * 5) **Think Critically explain whether or not the following statement is true: for any two objects, the one with the higher temperature always has more thermal energy.** //~False. Thermal energy depends on the amount of material and the potential energy of an object.//
 * 6) **Calculate the change in thermal energy of the water in a pond with a mass of 1000 kg and a specific heat of 4184 j/(kg C) if the water cools by 1 degree C.** //~Q=m(Tf-Ti)C=1000kg X 1 degree C X 4184 j/kg Degree C=4184000j (cools)//
 * 7) **Calculate the specific heat of a metal if 0.5 kg of the metal absorb 9000 j of heat as it warms by 10 degrees C.** //~9000J=(0.5kg)(10 degree C)(C)=9000J/(0.5)(10 degree C)=1900J/(kg0C)//

Section 2

 * 1) **Explain why materials that are good conductors of heat are poor insulators.** //~Becuase heat flows more rapidly from one place to another.//
 * 2) **Explain why the air temperature near the ceiling of a room tends to be warmer than near the floor**//. ~Becuase heat rises and cool air stays closer to the ground.//
 * 3) **Predict whether plastic foam, which contains pockets of air, would be a good conductor or a good insulator**//. ~ This would be a good insulator because the energy would not be pushed out.//
 * 4) **Describe how a convection current occurs. ~** //the dense that rises is less dense then becomes dense then goes back down to become less dense once agian and this keeps happening.//
 * 5) **Think Critically Several days after a snowfall, the roofs of some homes on a street have almost no snow on them, while the roofs of other houses are still snow-covered. Describe what would cause this difference.** //~ the sun could not be directly shinning on the roofs with snow as it is to the other ones. Or the roofs that dont have snow heats more then the other houses.//

Section 3

 * 1) **Explain for the thermal energy of a closed system changes with time.** //~The first law of thermodynamics says that it cant change.//
 * 2) **Compare and Contrast an active solar heating system with a radiator system**//.~ Radiator System is fuel burning to create heat and solar heating is the sun making heat.//
 * 3) **Explain whether or not a heat engine could be made 100 percent efficient by elminating friction//.//**//~ No, because it needs the warm temperature out side and inside the engine to be converted.//
 * 4) **Diagram how the thermal energy of the coolant changes as it flows in a refrigerator.[[image:http://www.saburchill.com/physics/images3/171103035.jpg]]**
 * 5) **Think Critically Suppose you vigorously shake a bottle of fruit juice. Predict how the temperature of the juice will change. Explain your reasoning**//.~ It will almost stay the same temperature it could warm because your hands are around it creating heat.//