Homework Due 11-18-10

Objective 1:

1) The three common temperature scales are Fahrenheit, Celsius, and Kelvin.
2) Thermal energy is related to temperature and heat because it depends on temperature of the object.
3) Having a high specific heat means that you would need a lot of energy to raise the temperature of the object.
4) An ice cube melts in your hand because your hand is a lot warmer than the ice cube and heat transfers to the cooler object so the heat from your hand transfers to the ice cube, which melts it.
5) Some materials get hot more quickly than others because they have a lower specific temperature than other materials.

Objective 2:

1) Thermometers measure temperature by using mercury, which expands when it gets hot and shrinks when it gets cold.
2) The three temperature are alike because they all give the value of the temperature of an object. The Kelvin and Celsius scales are alike because they go up by the same intervals. All three temperature scalse are different because they have different numbers for 0º.
3) 5º C is equal to 41º F.
4) 860º F is equal to 460º C.
5) 209,000 J

Objective 3:

1) The three forms of heat transfer are conduction, convection, and radiation.
2) Heat goes from the hotter substance to the cooler substance.
3) Conductors transfer energy well. They also feel cool to the touch. Some examples are silver and stainless steel. Insulators don't transfer thermal energy well. They feel warmer to the touch. Some examples are wood, wool, paper, and air.
4) A copper pipe would work better as a conductor because it would feel cooler to the touch, which means it is a conductor. It also transfers heat well, which is what conductors do.
5) I would build a tent because air is a very good insulator so once you set up the tent and close every spot where cold air can get in, then the air inside will insulate the tent.

Objective 4:

1) Matter changes state when its particle gain more energy.
2) The particles of the substance mover faster, eventually changing the substance's state of matter.
3) When matter is changing state, the temperature remains the same because the energy that is going into the substance is being used to change to substance's state of matter.
4) A solid melts when its particles gain more energy.
5) You should poke holes into a potato before baking it because there is a lot of water in the potato. When the water is heated up it evaporates and changes into air. When this happens more pressure is put on the walls of the potato and eventually there will be too much pressure and the potato will burst.

Objective 5:

1) Heat engines convert thermal energy into energy.
2) In an internal combustion engine, the expansion of the high temperature and pressure gases produced by combustion apply direct force to some part of the engine. An external combustion engine delivers energy to a working fluid.
3) Because internal combustion engines save energy by actually putting energy into the other parts of the engine and not doing it indirectly.
4) A liquid changes to a gas in the refrigerant of a refrigerator.
5) The system would stop circulating and the condenser wouldn't work as efficiently.


Sorry it was in so late... I got back late and I didn't have internet connection the whole time when I thought I would. I'm sorry!!!!!!