Specific Heat

B Block took time to define heat and relate temperature change to the direction of the flow of heat energy between objects. Heat will always flow spontaneously from the object at a higher temperature to an object of lower temperature, but we have to do work on the system to move heat up a temperature gradient. Work can also be done on an object to increase its internal energy, which is why when you hit a nail with a hammer, the nail head feels nice and warm. Tomorrow, we jump into the specific heat arena and the video I'll post below will be relevant to tomorrow's homework.

For C, E and F Blocks, specific heat was the topic of the day. Specific heat is the amount of heat energy we must add or remove to change the temperature of 1 kg of a substance by 1^°C. The higher the specific heat, the more energy necessary for a temperature change and the lower the specific heat, the less energy required. We looked at some examples of specific heat values in class and discussed how the specific heat differences between water, land and air contribute to the moderate climate for coastal areas. Our attention then moved to the method of determining specific heat (calorimetry) and how the basic principle behind calorimetry, aka conservation of energy, can be used to solve problems. Remember that the ΔT variable represents the difference between the final and initial temperatures and approach problems so that ΔT stays positive, even if you have to expand it to T₁ = T_f (opposite of our normal pattern. For C and E Blocks, we'll go over your specific heat homework in class before moving onto the concept of latent heat. For F Block, your homework problems are due on Monday, since tomorrow is lab day!

Here is a quick and dirty video for solving a calorimetry-type problem, which requires you determine the final temperature for the system: