Thermal Expansion Most materials expand when their temperature increases Individual atoms move further apart as their bonds are stretched. 3. If a solid isotropic object has a hole in it, what happens to the size of the hole when the temperature of the object increases? Explain below. O Week 8 Thermal Physics Specific Heat Capacity When heat energy, Q, is transferred into a system, the temperature of the system usually rises. It is found that AT O Q AT a - Where, AT is the increase in temperature, m is the mass of the substance. Combining these proportionalities we have: Q & MAT Introducing a constant of proportionality we can put these together in a formula: Q = mcAT 4. A 0.250 kg block of a pure material is heated from 20.0'C to 65.0"C by the addition of 4.35 kJ of energy. Calculate its specific heat below and using the specific heat capacity, identify the substance Week 8 Thermal Physics Heat of Transformation The amount of heat energy that causes 1 kg of a substance to undergo a phase change is called the heat of transformation of that substance. The symbol for heat of transformation is L. The heat required for mass m to undergo a phase change is Q=mlHeat of Transformation The amount of heat energy that causes 1 kg of a substance to undergo a phase change is called the heat of transformation of that substance. The symbol for heat of transformation is L. The heat required for mass m to undergo a phase change is Q=mL 5. How much heat is required to melt 0.800 kg of ice? The latent heat of melting ice is 33413'\\ Conduction can be summarized in a single formula: e) M Where,% is the rate of heat transfer (1/5) or watts (W) and k is the thermal conductivity of the material (W/m - K) Week 8 Thermal Physics 4 Calculate the rate of heat conduction through house walls that are 130 cm thick and that have an average thermal conductivity twice that of glass wool (glass wool has 3 Thermal conductivity of k: (1042 J/s.m.C). Assume there are no windows or doors The surface area of the walls is 120m2 and their inside surface is at 18.0'C, while their outside surface is at SDO'C