PY C4 H4:

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The velocity of a ball changes from m/s to m/s in 0.03 s, due to the gravitational attraction of the Earth and to air resistance. The mass of the ball is 130 grams. (a) What is the acceleration of the ball? a = x (m/s)/s (b) What is the rate of change of momentum of the ball? dp/dt = x (kg . m/s)/s (c) What is the net force acting on the ball? F net = X NUranium-233 (U233) has three more neutrons than uranium-235 (U235). Compared to the speed of sound in a bar of U235 play a role. , is the speed of sound in a bar of U233 higher, lower, or the same? There are several factors that (a) Chemically, the atoms of these two isotopes behave in essentially identical ways, since the number of protons (92) is identical and the clouds of 92 electrons are nearly identical. The interatomic distance, and the effective "stiffness'I of the interatomic bond, both depend on the chemical properties of the atoms. Therefore, which of the following statements are true? The effective stiffness of the interatomic "spring'I is greater for U238 because the mass is greater. The interatomic distance is the same for the two isotopes, because it depends on the size of the electron cloud, not the nuclear mass. An atom with more mass in the nucleus is bigger, so the distance between neighboring atoms is larger. The effective stiffness of the interatomic "spring'I is the same in the two isotopes, since this "spring" is a model for the interactions of the outer electrons, which are the same for different isotopes of the same atom. Question One mole of tungsten (6 x 1023 atoms) has a mass of 184 grams, and its density is 19.3 grams per cubic centimeter. You have a long thin bar of tungsten, 2.5 m long, with a square cross section, 0.05 cm on a side. You hang the rod vertically and attach a 50 kg mass to the bottom, and you observe that the bar becomes 1.36 cm longer. Calculate the effective stiffness of the interatomic bond, modeled as a "spring": kg = 3.6*1Ue4 x me You hang a heavy ball with a mass of 44 kg from a chromium rod 2.5 m long by 1.5 mm by 3.0 mm. You measure the stretch of the rod, and find that the rod stretched 0.000965 m. Using these experimental data, what value of Young's modulus do you get? 2 Y = me