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Concept explainers
Two thin rods are fastened to the inside of a circular ring as shown in Figure P2.42. One rod of length D is vertical, and the other of length L makes an angle θ with the horizontal. The two rods and the ring lie in a vertical plane. Two small beads are free to slide without friction along the rods. (a) If the two beads are released from rest simultaneously from the positions shown, use your intuition and guess which bead reaches the bottom first. (b) Find an expression for the time interval required for the red head to fall from point Ⓐ to point Ⓒ in terms of g and D. (c) Find an expression for the time interval required for the blue bead to slide from point Ⓑ to point Ⓒ in terms of g, L, and θ. (d) Show that the two time intervals found in parts (b) and (c) are equal. Hint: What is the angle between the chords of the circle Ⓐ Ⓑ and Ⓑ Ⓒ? (e) Do these results surprise you? Was your intuitive guess in part (a) correct? This problem was inspired by an article by Thomas B. Greenslade, Jr., “Galileo’s Paradox,” Phys. Teach. 46, 294 (May 2008).
Figure P2.42
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Chapter 2 Solutions
Physics for Scientists and Engineers with Modern Physics
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- Please don't use Chatgpt will upvote and give handwritten solutionarrow_forward6. We used the constant volume heat capacity, Cv, when we talked about thermodynamic cycles. It acts as a proportionality constant between energy and temperature: dU = C₁dT. You can also define a heat capacity for constant pressure processes, Cp. You can think of enthalpy playing a similar role to energy, but for constant pressure processes δαρ C = (37) - Sup Ср ат P = ат Starting from the definition of enthalpy, H = U + PV, find the relationship between Cy and Cp for an ideal gas.arrow_forwardPure membranes of dipalmitoyl lecithin phospholipids are models of biological membranes. They melt = 41°C. Reversible melting experiments indicate that at Tm AHm=37.7 kJ mol-1. Calculate: A. The entropy of melting, ASm- B. The Gibbs free energy of melting, AGm- C. Does the membrane become more or less ordered upon melting? D. There are 32 rotatable CH2 CH2 bonds in each molecule that can rotate more freely if the membrane melts. What is the increase in multiplicity on melting a mole of bonds?arrow_forward
- 5. Heat capacity often has a temperature dependence for real molecules, particularly if you go over a large temperature range. The heat capacity for liquid n-butane can be fit to the equation Cp(T) = a + bT where a = 100 J K₁₁ mol¹ and b = 0.1067 J K² mol¹ from its freezing point (T = 140 K) to its boiling point (T₁ = 270 K). A. Compute AH for heating butane from 170 K to 270 K. B. Compute AS for the same temperature range.arrow_forward4. How much energy must be transferred as heat to cause the quasi-static isothermal expansion of one mole of an ideal gas at 300 K from PA = 1 bar to PB = 0.5 bar? A. What is VA? B. What is VB? C. What is AU for the process? D. What is AH for the process? E. What is AS for the process?arrow_forward1. The diagram shows the tube used in the Thomson experiment. a. State the KE of the electrons. b. Draw the path of the electron beam in the gravitational field of the earth. C. If the electric field directed upwards, deduce the direction of the magnetic field so it would be possible to balance the forces. electron gun 1KVarrow_forward
- as a hiker in glacier national park, you need to keep the bears from getting at your food supply. You find a campground that is near an outcropping of ice. Part of the outcropping forms a feta=51.5* slopeup that leads to a verticle cliff. You decide that this is an idea place to hang your food supply out of bear reach. You put all of your food into a burlap sack, tie a rope to the sack, and then tie a bag full of rocks to the other end of the rope to act as an anchor. You currently have 18.5 kg of food left for the rest of your trip, so you put 18.5 kg of rocks in the anchor bag to balance it out. what happens when you lower the food bag over the edge and let go of the anchor bag? Determine the acceleration magnitude a of the two-bag system when you let go of the anchor bag?arrow_forward2. A thin Nichrome wire is used in an experiment to test Ohm's law using a power supply ranging from 0 to 12 V in steps of 2 V. Why isn't the graph of I vs V linear? 1. Nichrome wire does obey Ohm's law. Explain how that can that be true given the results abovearrow_forward1. The average KE and temperature in Kelvin of the molecules of a gas are related by the equation KE = 3/2 KT where k is the Boltzmann constant 1.38 x 10 m² kg s². The diagram shows the energy levels for a Hydrogen atom. Energy/eV 0.00 -1.51 3.39 13.58 Use this information to show that Hydrogen at room temperature will not emit light. 2. When hydrogen burns in oxygen 241.8 kJ of energy are released per mole. Show that this reaction can produce light.arrow_forward
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