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A 128.0-N carton is pulled up a frictionless baggage ramp inclined at 30.0 above the horizontal by a rope exerting a 72.0-N pull parallel to the ramps surface. If the carton travels 5.20 m along the... The black dots at the top of Fig. Q2.2 represent a series of high-speed photographs of an insect flying in a straight line from left to right (in the positive x-direction). Which of the graphs in... A 1.35-kg object is attached to a horizontal spring of force constant 2.5 N/cm. The object is started oscillating by pulling it 6.0 cm from its equilibrium position and releasing it so that it is... The jet pump injects water at V 1 = 40 m/s through a 7.6 cm pipe and entrains a secondary flow of water V 2 = 3 m/s in the annular region around the small pipe. The two flows become fully mixed... Salt water containing 1.92 lb/gal of salt flows at a fixed rate of 2 gal/min into a 100-gal tank, initially filled with fresh water. The density of the incoming solution is 71.8 lb/ft 3 . The... Water is flowing through a large circular conduit with a velocity profile given by the equation v = 9(1 - r 2 /16) fps. What is the average water velocity in the 1.5-ft pipe? 8 ft d = 1.5 ft The velocity vector in a two-dimensional flow is given by the expression v = 10e x + 7xe y m/s when x is measured in meters. Determine the component of the velocity that makes a -30 angle with the x... You are doing exercises on a Nautilus machine in a gym to strengthen your deltoid (shoulder) muscles. Your arms are raised vertically and can pivot around the shoulder joint, and you grasp the cable... A uniform beam is suspended horizontally and attached to a wall by a small hinge (Fig. Q11.19). What are the directions (upward or downward, and to the left or the right) of the components of the... A large turntable with radius 6.00 m rotates about a fixed vertical axis, making one revolution in 8.00 s. The moment of inertia of the turntable about this axis is 1200 kg m 2 . You stand,... Two identical balls, A and B, are each attached to very light string, and each string is wrapped around the rim of a frictionless pulley of mass M. The only difference is that the pulley for ball A... Water flows steadily through the piping junction, entering section 1 at 0.0013 m 3 /s. The average velocity at section 2 is 2.1 m/s. A portion of the flow is diverted through the shower head, which... Water enters a 4-in. square channel as shown at a velocity of 10 fps. The channel converges to a 2-in. square configuration as shown at the discharge end. The outlet section is cut at 30° to the... Biologists think that some spiders tune strands of their web to give enhanced response at frequencies corresponding to those at which desirable prey might struggle. Orb spider web silk has a typical... We can make a simple model of the human vocal tract as an open-closed tube extending from the opening of the mouth to the diaphragm. What is the length of this tube if its fundamental frequency... The two highest-pitch strings on a violin are tuned to 440 Hz (the A string) and 659 Hz (the E string). What is the ratio of the mass of the A string to that of the E string? Violin strings are all... When a space capsule returns to earth, its surfaces get very hot as it passes through the atmosphere at high speed. Has the space capsule been heated? If so, what was the source of the heat? If not,... A 2000 cm 3 container holds 0.10 mol of helium gas at 300C. How much work must be done to compress the gas to 1000 cm 3 at (a) Constant pressure (b) Constant temperature? How much heat is needed to change 20 g of mercury at 20C into mercury vapor at the boiling point? The gas cylinder in Figure Q19.11 is well insulated on all sides. The piston can slide without friction. Many small masses on top of the piston are removed one by one until the total mass is reduced... A container holds 1.0 g of oxygen at a pressure of 8.0 atm. a. How much heat is required to increase the temperature by 100C at constant pressure? b. How much will the temperature increase if this... A gas cylinder holds 0.10 mol of O 2 at 150C and a pressure of 3.0 atm. The gas expands adiabatically until the volume is doubled. What are the final (a) Pressure (b) Temperature? A 10 m 14 m house is built on a 12-cm-thick concrete slab. What is the heat-loss rate through the slab if the ground temperature is 5C while the interior of the house is 22C? You are boiling pasta and absentmindedly grab a copper stirring spoon rather than your wooden spoon. The copper spoon has a 20 mm 1.5 mm rectangular cross section, and the distance from the boiling... At what speed does a 1000 kg compact car have the same kinetic energy as a 20,000 kg truck going 25 km/h? Consider the circuit shown in Fig. P25.73. The emf source has negligible internal resistance. The resistors have resistances R 1 = 6.00 Ω and R 2 = 4.00 Ω. The capacitor has... An overhead transmission cable for electrical power is 2000 m long and consists of two parallel copper wires, each encased in insulating material. A short circuit has developed somewhere along the... A 25 kg box sliding to the left across a horizontal surface is brought to a halt in a distance of 35 cm by a horizontal rope pulling to the right with 15 N tension. How much work is done by (a)... A particle moving to the left is slowed by a force pushing to the right. Is the work done on the particle positive or negative? Or is there not enough information to tell? Explain. A 2.0 kg book is lying on a 0.75-m-high table. You pick it up and place it on a bookshelf 2.25 m above the floor. a. How much work does gravity do on the book? b. How much work does your hand do on... A 20 g particle is moving to the left at 30 m/s. A force on the particle causes it to move the the right at 30 m/s. How much work is done by the force? You throw a 5.5 g coin straight down at 4.0 m/s from a 35-m-high bridge. a. How much work does gravity do as the coin falls to the water below? b. What is the speed of the coin just as it hits the... The two ropes seen in FIGURE EX9.18 are used to lower a 255 kg piano 5.00 m from a second-story window to the ground. How much work is done by each of the three forces? 1830 N 60% 1295 N 45 2500 N... FIGURE EX9.20 is the force-versus-position graph for a particle moving along the x-axis. Determine the work done on the particle during each of the three intervals 01 m, 12 m, and 23 m. F, (N) 4 -x... Given the following expression for the pressure field where x, y, and z are space coordinates, t is time, and P 0 , p, V , and L are constants. Find the pressure gradient Vot 2 P = Po +pV% Z +3 L3 A pressure of 10 MPa is applied to 0.25 m 3 of a liquid, causing a volume reduction of 0.005 cm 3 . Determine the bulk modulus of elasticity. An object is thrown straight up into the air and feels no air resistance. How can the object have an acceleration when it has stopped moving at its highest point? You are on the west bank of a river that is flowing north with a speed of 1.2 m/s. Your swimming speed relative to the water is 1.5 m/s, and the river is 60 m wide. What is your path relative to the... A helium balloon hovers in midair, neither ascending nor descending. Is it in equilibrium? What forces act on it? Some people say that the force of inertia (or force of momentum) throws the passengers forward when a car brakes sharply. What is wrong with this explanation? (a) An ordinary flea has a mass of 210 g. How many newtons does it weigh? (b) The mass of a typical froghopper is 12.3 mg. How many newtons does it weigh? (c) A house cat typically weighs 45 N. How... A small car of mass 380 kg is pushing a large truck of mass 900 kg due east on a level road. The car exerts a horizontal force of 1600 N on the truck. What is the magnitude of the force that the... When a string barely strong enough lifts a heavy weight, it can lift the weight by a steady pull; but if you jerk the string, it will break. Explain in terms of Newtons laws of motion. Boxes A and B are connected to each end of a light vertical rope (Fig. P4.49). A constant upward force F = 80.0 N is applied to box A. Starting from rest, box B descends 12.0 m in 4.00 s. The tension... You throw a baseball straight upward. If you do not ignore air resistance, how does the time required for the ball to reach its maximum height compare to the time required for it to fall from its... A segment of DNA is put in place and stretched. Figure P7.82 shows a graph of the force exerted on the DNA as a function of the displacement of the stage. Based on this graph, which statement is the... A flywheel rotates with constant angular velocity. Does a point on its rim have a tangential acceleration? A radial acceleration? Are these accelerations constant in magnitude? In direction? In each... When you stand with bare feet in a wet bathtub, the grip feels fairly secure, and yet a catastrophic slip is quite possible. Explain this in terms of the two coefficients of friction. You are balancing a wrench by suspending it at a single point. Is the equilibrium stable, unstable, or neutral if the point is above, at, or below the wrenchs center of gravity? In each case give the... Certain features of a person, such as height and mass, are fixed (at least over relatively long periods of time). Are the following features also fixed? (a) Location of the center of gravity of the... When sound travels from air into water, does the frequency of the wave change? The speed? The wavelength? Explain your reasoning. A 60.0-m-long brass rod is struck at one end. A person at the other end hears two sounds as a result of two longitudinal waves, one traveling in the metal rod and the other traveling in air. What is... Many automobile engines have cast-iron cylinders and aluminum pistons. What kinds of problems could occur if the engine gets too hot? (The coefficient of volume expansion of cast iron is... Why do frozen water pipes burst? Would a mercury thermometer break if the temperature went below the freezing temperature of mercury? Why or why not? Why is it sometimes possible to loosen caps on screw-top bottles by dipping the capped bottle briefly into hot water? A student asserts that a suitable unit for specific heat is 1 m 2 /s 2 C. Is she correct? Why or why not? When you first step out of the shower, you feel cold. But as soon as you are dry you feel warmer, even though the room temperature does not change. Why? A brass rod 12.0 cm long, a copper rod 18.0 cm long, and an aluminum rod 24.0 cm longeach with cross-sectional area 2.30 cm 3 are welded together end to end to form a rod 54.0 cm long, with copper as... During your mechanical engineering internship, you are given two uniform metal bars A and B, which are made from different metals, to determine their thermal conductivities. Measuring the bars, you... It is not correct to say that a body contains a certain amount of heat, yet a body can transfer heat to another body. How can a body give away something it does not have in the first place? When you blow on the back of your hand with your mouth wide open, your breath feels warm. But if you partially close your mouth to form an o and then blow on your hand, your breath feels cool. Why? In a hospital, pure oxygen may be delivered at 50 psi (gauge pressure) and then mixed with N 2 O. What volume of oxygen at 20C and 50 psi (gauge pressure) should be mixed with 1.7 kg of N 2 O to get... The two sides of the DNA double helix are connected by pairs of bases (adenine, thymine, cytosine, and guanine). Because of the geometric shape of these molecules, adenine bonds with thymine and... A student asked, Since electrical potential is always proportional to potential energy, why bother with the concept of potential at all? How would you respond? If E(vector) is zero throughout a certain region of space, is the potential necessarily also zero in this region? Why or why not? If not, what can be said about the potential? During lightning strikes from a cloud to the ground, currents as high as 25,000 A can occur and last for about 40 ms. How much charge is transferred from the cloud to the earth during such a strike? Can the potential difference between the terminals of a battery ever be opposite in direction to the emf ? If it can, give an example. If it cannot, explain why not. Nerve cells transmit electric signals through their long tubular axons. These signals propagate due to a sudden rush of Na + ions, each with charge +e, into the axon. Measurements have revealed that... Two 120-V light bulbs, one 25-W and one 200-W, were connected in series across a 240-V line. It seemed like a good idea at the time, but one bulb burned out almost immediately. Which one burned out,... A real battery, having nonnegligible internal resistance, is connected across a light bulb as shown in Fig. Q26.10. When the switch S is closed, what happens to the brightness of the bulb? Why?... A 6.00 F capacitor that is initially uncharged is connected in series with a 5.00 resistor and an emf source with = 50.0 V and negligible internal resistance. At the instant when the resistor is... In the circuit shown in Fig. E26.18, ε = 36.0 V, R 1 = 4.00 Ω, R 2 = 6.00 Ω, and R 3 = 3.00 Ω. (a) What is the potential difference V ab between... In a Hall-effect experiment, is it possible that no transverse potential difference will be observed? Under what circumstances might this happen? In a cyclotron, the orbital radius of protons with energy 300 keV is 16.0 cm. You are redesigning the cyclotron to be used instead for alpha particles with energy 300 keV. An alpha particle has... To use a larger sample, the experimenters construct a solenoid that has the same length, type of wire, and loop spacing but twice the diameter of the original. How does the maximum possible magnetic... The current in the long, straight wire AB shown in Fig. E29.7 is upward and is increasing steadily at a rate di/dt. (a) At an instant when the current is i, what are the magnitude and direction of... A rectangular loop of wire with dimensions 1.50 cm by 8.00 cm and resistance R = 0.600 Ω is being pulled to the right out of a region of uniform magnetic field. The magnetic field has... A 0.250-m-long bar moves on parallel rails that are connected through a 6.00-Ω resistor, as shown in Fig. E29.33, so the apparatus makes a complete circuit. You can ignore the resistance... Consider the circuit in Exercise 30.23. (a) Just after the circuit is completed, at what rate is the battery supplying electrical energy to the circuit? (b) When the current has reached its final... If part of the magnet develops resistance and liquid helium boils away, rendering more and more of the magnet nonsuperconducting, how will this quench affect the time for the current to drop to half... What is the dc impedance of the electrode, assuming that it behaves as an ideal capacitor? (a) 0; (b) Infinite; (c) 2 10 4 ; (d) 2 10 6 . An individual cell such as an egg cell (an ovum, produced... If the electrode oscillates between two points 20 mm apart at a frequency of (5000/)Hz, what is the electrodes impedance? (a) 0; (b) Infinite; (c) 2 10 4 ; (d) 2 10 6 . An individual cell such as... If the frequency at which the electrode is oscillated is increased to a very large value, the electrodes impedance (a) Approaches infinity; (b) Approaches zero; (c) Approaches a constant but nonzero... Light requires about 8 minutes to travel from the sun to the earth. Is it delayed appreciably by the earths atmosphere? Explain. Sunlight or starlight passing through the earths atmosphere is always bent toward the vertical. Why? Does this mean that a star is not really where it appears to be? Explain. A beam of light goes from one material into another. On physical grounds, explain why the wavelength changes but the frequency and period do not. A student claimed that, because of atmospheric refraction (see Discussion Question Q33.2), the sun can be seen after it has set and that the day is therefore longer than it would be if the earth had... When a sheet of plastic food wrap is placed between two crossed polarizers, no light is transmitted. When the sheet is stretched in one direction, some light passes through the crossed polarizers.... Ordinary glasses are worn in front of the eye and usually 2.0 cm in front of the eyeball. Suppose that the person in Exercise 34.52 prefers ordinary glasses to contact lenses. What focal length... A person with a near point of 85 cm, but excellent distant vision, normally wears corrective glasses. But he loses them while traveling. Fortunately, he has his old pair as a spare. (a) If the lenses... A researcher measures the thickness of a layer of benzene (n = 1.50) floating on water by shining monochromatic light onto the film and varying the wavelength of the light. She finds that light of... An investigator proposes to study the mass-transfer process for the dissolution of a single solid sphere suspended within a turbulent flow stream. Predict the variables that would be used to explain... Find the pressure gradient at point (a,b) when the pressure field is given by where p, v, a, and b are constants. P = P,V (sin - sin + 2 y a. Find the temperature gradient at point (a, b) at time t = (L 2 /a) ln e when the temperature field is given by where T 0 , a, a, and b are constants. T = Toe-at/4L' sin * cosh: y a Determine the height to which water at 68C will rise in a clean capillary tube having a diameter of 0.2875 cm. Determine the difference in pressure between the inside and outside of a soap film bubble at 20C if the diameter of the bubble is 4 mm. Determine the diameter of the glass tube necessary to keep the capillary-height change of water at 30C less than 1 mm. In Problem 2.2, find the depth at which the net force on the tank is zero. Data From Problem 2.2 The open end of a cylindrical tank 2 ft in diameter and 3 ft high is submerged in water as shown. If... Determine the depth change to cause a pressure increase of 1 atm for (a) water, (b) sea water (SG = 1.0250), and (c) mercury (SG = 13.6). A dam spillway gate holds back water of depth h. The gate weights 500 1b/ft and is hinged at A. At what depth of water will the gate rise and permit water to flow under it? 15 ft CG 6 ft 60, 10 ft
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