PHYSICS (SOLUTIONS) Essay Example | Topics and Well Written Essays - 750 words

PHYSICS (SOLUTIONS) - Essay Example100Pa). Here, it is essential that the drag decreases exponentially, i.e. without local minimums and maximums (with the ejection of atmospheric fluctuations) so, our criterion mb is valid. Roughly, from the chart attached we can localize km, say, km.e) Let us analyze the pressure curve . It is necessary to rase that determine of altitude ar in log-scale. Nevertheless, even in linear scale dependence is non linear see (Atmospheric pressure 2008) and (Ahren 2000). This can be explained by exponential atmosphere model. This is very ferocious model for a column of gas extending to a great height see details in (Feynman et al 1964). Such gas column is sibylline to be at thermal equilibrium without any disturbances, so in the model. Model gives an obvious relationship where is the mass of the gas molecule (supposed to be unvarying in the model), is the acceleration due to gravity, and is the total number of the gas molecules in the unit section o f a gas column. Solution of this relationship is here . So, the pressure exponentially decreases with increasing of altitude. Such decreasing depends upon the mass of gas molecule the pressure of lightweight gases (e.g. hydrogen) decreases more slowly with altitude then the pressure of heavy-weight gases (e.g. oxygen).Here, and are weights of a ball... oxygen).Task 2This task can be solved using Archimedes principle. Let us make schematic illustration for a helium balloon and all the forces applied to it Here, and are weights of a balloon and helium inside it, is the net force of buoyancy (for both balloon and helium inside). In accordance with Archimedes principle, or the law of upthrust, a balloon is buoyed up by a force equal to the weight of the displaced air. A balloon is in state of rest when resulting force equals to zero, i.e. when .a) A balloon is assumed to be a sphere with a diameter of 20cm, so m. Hence, its volume is , or m3, or around litres (because 1 litre equals to m3).b) Let us estimate the mass of helium in the balloon. Let us suppose that helium is an ideal gas at and atmosphere. The ideal gas law gives volume occupied by a mole of an ideal gas litres here is universal gas constant (Feynman et al 1964). Therefore, the balloon contains moles of helium. The relative atomic mass of helium is 4, so a mole of helium weights 4 grams. Hence, helium in the balloon weights approx. grams. c) Using the graph attached for the task 1, namely dependence , let us define where km. Roughly, mb, say, mb or atmosphere. Let us estimate absorption of the air at the altitude km. For exponential model of atmosphere we have see (Feynman et al 1964). The ideal gas law or allows us to make estimations in name of air density here grams per mole is the mean molar mass of air. For isothermal atmosphere () , so . Then, , so . Let us compute , the density of air at sea level grams per litre. Let us estimate , the density of the air at the altitude km or grams per litre.d) It is necessary to note that almost all numeric