Volumetric and Liquid Thermal Expansion Exercises – In this video lesson, we will solve exercises related to the theory seen in our last lesson. Remember that it is vitally important that you TRY to solve the exercises, pause and do it!!! Exercise 1 (PUC-RS) A parallelepiped at 10 ºC has dimensions equal to 10 x 20 x 30 cm, and is made of a material with linear thermal expansion of 8.0 x 10-6 C-1. What is the increase in volume that it undergoes when its temperature is raised to 110 ºC? Exercise 2 (Mackenzie-SP) In an experiment to determine the coefficient of linear expansion of glass, we took a glass bottle with a volume of 1,000 cm³ and filled it completely with mercury (coefficient of volumetric expansion = 1.8.10-4 ºC-1). After raising the temperature of the set to 100 °C, we observe that 3.0 cm³ of mercury overflow. Thus, we can state that the coefficient of linear expansion of the glass that makes up this flask is: a) 5.0. 10-5 ºC-1 b) 4.0. 10-5 ºC-1 c) 3.0. 10-5 ºC-1 d) 2.0. 10-5 ºC-1 e) 1.0. 10-5 ºC-1 Be sure to watch the video about the theory of Thermal Expansion of Solids and Liquids. Subscribe to the channel to stay updated, Thermology videos, always on Thursdays. Thermal Expansion of Solids - Linear Expansion Volumetric Expansion, The Effects of Temperature on Volumetric Expansion Thermal Expansion of Solids, in this series of video classes we will address the expansion of solids. As we have already studied in previous classes, temperature measures the state of agitation of molecules and this directly affects the dimensions of a body. The higher the temperature, the greater the agitation. So, in these next classes we will establish a relationship between the variation in temperature and the variation in the dimensions of the body. The study of the expansion of bodies is divided into two segments, solids and liquids (gases occupy the volume of the container, therefore they do not have defined volumes). What we will study in the first class is linear expansion and surface expansion, and in the second class we will see volumetric expansion and that of liquids. In certain cases, it is not necessary to study the variations in the measurements of bodies in all dimensions. The first of these that we will study occurs in wires, bars, rails, in short, in bodies whose length is much greater than their width and thickness. The variation in the length of a body (ΔL) is directly proportional to the length of the body (L0), after all, if we have a molecule moving, when we increase its agitation it will occupy a slightly larger “space”. But if we have a larger number of molecules, and each one ends up occupying a larger “space”, when we add all these spaces together we will have a greater increase. It is also directly proportional to the temperature variation (Δθ), for obvious reasons, and it also depends on the material, where there is a linear expansion coefficient (α), therefore, the linear expansion equation is: ΔL = L0. α. Δθ Surface expansion occurs in situations where the length and width are much greater than the thickness, for example in sheets and plates. Here we will study the variation in the surface area of ​​the body. A good approximation can be given by: ΔA = A0.β. Δθ Where A is the area and β is the surface expansion coefficient, and β = 2.α, but this is an approximation! Volumetric expansion occurs when length, width and thickness (or height) are of the same order of magnitude, such as blocks and engines. Here we will study the variation in the volume of the body, a good approximation can be given by: ΔV = V0.γ. Δθ Where V is volume and γ is the coefficient of surface expansion, and γ = 3.α, but here it is also an approximation! Liquids only have a volumetric coefficient and expand much more than liquids. When heating a container such as a beaker, we can measure the variation of a liquid, but this variation is apparent, after all the beaker also expands, but less. We call this measurement apparent expansion, the real expansion of the liquid is the apparent plus that of the beaker. Contact: Email - [email protected] Blog: https://fisicaretek.wordpress.com/ Facebook: / andre.retek Twitter: / andreretek Video Link: • Volumetric Expansion Exercises and...