A small ferryboat is 4.00 m wide and 6.00 m long. When a loaded truck pulls onto it, the boat sinks an additional 4.00 cm into the river. What is the weight of the truck?
> The viscous force on an oil drop is measured to be equal to 3.0 x 10-13 N when the drop is falling through air with a speed of 4.5 x 10-4 m/s. If the radius of the drop is 2.5 x 10-6 m, what is the viscosity of air?
> Glycerin in water diffuses along a horizontal column that has a cross-sectional area of 2.0 cm2. The concentration gradient is 3.0 x 10-2 kg/m4, and the diffusion rate is found to be 5.7 x 10-15 kg/s. Determine the diffusion coefficient.
> Sucrose is allowed to diffuse along a 10.- cm length of tubing filled with water. The tube is 6.0 cm2 in cross-sectional area. The diffusion coefficient is equal to 5.0 x 10-10 m2/s, and 8.0 x 10-14 kg is transported along the tube in 15 s. What is the d
> A constant net torque is applied to an object. Which one of the following will not be constant? (a) Angular acceleration, (b) Angular velocity, (c) Moment of inertia, or (d) Center of gravity.
> The aorta in humans has a diameter of about 2.0 cm, and at certain times the blood speed through it is about 55 cm/s. Is the blood flow turbulent? The density of whole blood is 1050 kg/m3, and its coefficient of viscosity is 2.7 x 10-3 N · s/m2.
> What radius needle should be used to inject a volume of 500. cm3 of a solution into a patient in 30.0 min? Assume the length of the needle is 2.5 cm and the solution is elevated 1.0 m above the point of injection. Further, assume the viscosity and densit
> A hypodermic needle is 3.0 cm in length and 0.30 mm in diameter. What pressure difference between the input and output of the needle is required so that the flow rate of water through it will be 1 g/s? (Use 1.0 x 10-3 Pa · s as the viscosity of water.)
> Spherical particles of a protein of density 1.8 g/cm3 are shaken up in a solution of 20°C water. The solution is allowed to stand for 1.0 h. If the depth of water in the tube is 5.0 cm, find the radius of the largest particles that remain in solution at
> The pulmonary artery, which connects the heart to the lungs, has an inner radius of 2.6 mm and is 8.4 cm long. If the pressure drop between the heart and lungs is 400 Pa, what is the average speed of blood in the pulmonary artery?
> A straight horizontal pipe with a diameter of 1.0 cm and a length of 50 m carries oil with a coefficient of viscosity of 0.12 N · s/m2. At the output of the pipe, the flow rate is 8.6 x 10-5 m3/s and the pressure is 1.0 atm. Find the gauge pressure at th
> A thin 1.5-mm coating of glycerine has been placed between two microscope slides of width 1.0 cm and length 4.0 cm. Find the force required to pull one of the microscope slides at a constant speed of 0.30 m/s relative to the other slide.
> The block of ice (temperature 0°C) shown in Figure P9.53 is drawn over a level surface lubricated by a layer of water 0.10 mm thick. Determine the magnitude of the force F( needed to pull the block with a constant speed of 0.50 m/s. At 0Â
> Whole blood has a surface tension of 0.058 N/m and a density of 1050 kg/m3. To what height can whole blood rise in a capillary blood vessel that has a radius of 2.0 x 10-6 m if the contact angle is zero?
> A certain fluid has a density of 1080 kg/m3 and is observed to rise to a height of 2.1 cm in a 1.0-mm-diameter tube. The contact angle between the wall and the fluid is zero. Calculate the surface tension of the fluid.
> Using a screwdriver, you try to remove a screw from a piece of furniture, but can’t get it to turn. To increase the chances of success, you should use a screwdriver that (a) Is longer, (b) Is shorter, (c) Has a narrower handle, or (d) Has a wider handle.
> To lift a wire ring of radius 1.75 cm from the surface of a container of blood plasma, a vertical force of 1.61 x 10-2 N greater than the weight of the ring is required. Calculate the surface tension of blood plasma from this information.
> A square metal sheet 3.0 cm on a side and of negligible thickness is attached to a balance and inserted into a container of fluid. The contact angle is found to be zero, as shown in Figure P9.49a, and the balance to which the metal sheet is attached read
> The Venturi tube shown in Figure P9.48 may be used as a fluid flowmeter. Suppose the device is used at a service station to measure the flow rate of gasoline (p = 7.00 x 102 kg/m3) through a hose having an outlet radius of 1.20 cm. If the difference in p
> Old Faithful geyser in Yellowstone Park erupts at approximately 1-hour intervals, and the height of the fountain reaches 40.0 m (Fig. P9.47). (a) Consider the rising stream as a series of separate drops. Analyze the free-fall motion of one of the drops t
> Water is pumped through a pipe of diameter 15.0 cm from the Colorado River up to Grand Canyon Village, on the rim of the canyon. The river is at 564 m elevation and the village is at 2096 m. (a) At what minimum pressure must the water be pumped to arrive
> The inside diameters of the larger portions of the horizontal pipe depicted in Figure P9.45 are 2.50 cm. Water flows to the right at a rate of 1.80 x 10-4 m3/s. Determine the inside diameter of the constriction. Figure P9.45:
> A large storage tank, open to the atmosphere at the top and filled with water, develops a small hole in its side at a point 16.0 m below the water level. If the rate of flow from the leak is 2.50 x 10-3 m3/min, determine (a) The speed at which the water
> A jet of water squirts out horizontally from a hole near the bottom of the tank shown in Figure P9.43. If the hole has a diameter of 3.50 mm, what is the height h of the water level in the tank? Figure P9.43:
> Water moves through a constricted pipe in steady, ideal flow. At the lower point shown in Figure P9.42, the pressure is 1.75 x 105 Pa and the pipe radius is 3.00 cm. At the higher point located at y = 2.50 m, the pressure is 1.20 x 105 Pa and the pipe ra
> In a water pistol, a piston drives water through a larger tube of radius 1.00 cm into a smaller tube of radius 1.00 mm as in Figure P9.41. (a) If the pistol is fired horizontally at a height of 1.50 m, use ballistics to determine the time it takes water
> One container is filled with argon gas and another with helium gas. Both containers are at the same temperature. Which atoms have the higher rms speed? (a) Argon, (b) Helium, (c) They have the same speed, or (d) Not enough information to say.
> A man attaches a divider to an outdoor faucet so that water flows through a single pipe of radius 9.00 mm into two pipes, each with a radius of 6.00 mm. If water flows through the single pipe at 1.25 m/s, calculate the speed of the water in the narrower
> A jet airplane in level flight has a mass of 8.66 x 104 kg, and the two wings have an estimated total area of 90.0 m2. (a) What is the pressure difference between the lower and upper surfaces of the wings? (b) If the speed of air under the wings is 225 m
> When a person inhales, air moves down the bronchus (windpipe) at 15 cm/s. The average flow speed of the air doubles through a constriction in the bronchus. Assuming incompressible flow, determine the pressure drop in the constriction.
> A hypodermic syringe contains a medicine with the density of water (Fig. P9.37). The barrel of the syringe has a cross-sectional area of 2.50 x 10-5 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force F( of magnitud
> A liquid (p = 1.65 g/ cm3) flows through a horizontal pipe of varying cross section as in Figure P9.36. In the first section, the cross-sectional area is 10.0 cm2, the flow speed is 275 cm/s, and the pressure is 1.20 x 105 Pa. In the second section, the
> (a) Calculate the mass flow rate (in grams per second) of blood (p = 1.0 g/cm3) in an aorta with a cross-sectional area of 2.0 cm2 if the flow speed is 40. cm/s. (b) Assume that the aorta branches to form a large number of capillaries with a combined cro
> Water flowing through a garden hose of diameter 2.74 cm fills a 25.0-L bucket in 1.50 min. (a) What is the speed of the water leaving the end of the hose? (b) A nozzle is now attached to the end of the hose. If the nozzle diameter is one-third the diamet
> A large water tank is 3.00 m high and filled to the brim, the top of the tank open to the air. A small pipe with a faucet is attached to the side of the tank, 0.800 m above the ground. If the valve is opened, at what speed will water come out of the pipe
> A horizontal pipe narrows from a radius of 0.250 m to 0.100 m. If the speed of the water in the pipe is 1.00 m/s in the larger-radius pipe, what is the speed in the smaller pipe?
> A 1.00-kg beaker containing 2.00 kg of oil (density = 916 kg/m3) rests on a scale. A 2.00-kg block of iron is suspended from a spring scale and is completely submerged in the oil (Fig. P9.31). Find the equilibrium readings of both scales. Figure P9.31:
> Why doesn’t the melting of ocean-based ice raise as much concern as the melting of land-based ice?
> An object weighing 300 N in air is immersed in water after being tied to a string connected to a balance. The scale now reads 265 N. Immersed in oil, the object appears to weigh 275 N. Find (a) The density of the object and (b) The density of the oil.
> A sample of an unknown material appears to weigh 300. N in air and 200. N when immersed in alcohol of specific gravity 0.700. What are (a) The volume and (b) The density of the material?
> A light spring of force constant k = 160 N/m rests vertically on the bottom of a large beaker of water (Fig. P9.28a). A 5.00-kg block of wood (density = 650 kg/m3) is connected to the spring, and the block–spring system is allowed to co
> A cube of wood having an edge dimension of 20.0 cm and a density of 650. kg/m3 floats on water. (a) What is the distance from the horizontal top surface of the cube to the water level? (b) What mass of lead should be placed on the cube so that the top of
> The gravitational force exerted on a solid object is 5.00 N as measured when the object is suspended from a spring scale as in Figure P9.26a. When the suspended object is submerged in water, the scale reads 3.50 N (Fig. P9.26b). Find the density of the o
> On October 21, 2001, Ian Ashpole of the United Kingdom achieved a record altitude of 3.35 km (11000 ft) powered by 600 toy balloons filled with helium. Each filled balloon had a radius of about 0.50 m and an estimated mass of 0.30 kg. (a) Estimate the to
> The average human has a density of 945 kg/m3 after inhaling and 1020 kg/m3 after exhaling. (a) Without making any swimming movements, what percentage of the human body would be above the surface in the Dead Sea (a body of water with a density of about 12
> A spherical weather balloon is filled with hydrogen until its radius is 3.00 m. Its total mass including the instruments it carries is 15.0 kg. (a) Find the buoyant force acting on the balloon, assuming the density of air is 1.29 kg/m3. (b) What is the n
> A large balloon of mass 226 kg is filled with helium gas until its volume is 325 m3. Assume the density of air is 1.29 kg/m3 and the density of helium is 0.179 kg/m3. (a) Draw a force diagram for the balloon. (b) Calculate the buoyant force acting on the
> A hot-air balloon consists of a basket hanging beneath a large envelope filled with hot air. A typical hot-air balloon has a total mass of 545 kg, including passengers in its basket, and holds 2.55 x 103 m3 of hot air in its envelope. If the ambient air
> Two spheres are made of the same metal and have the same radius, but one is hollow and the other is solid. The spheres are taken through the same temperature increase. Which sphere expands more? (a) Solid sphere, (b) Hollow sphere, (c) They expand by the
> A 62.0-kg survivor of a cruise line disaster rests atop a block of Styrofoam insulation, using it as a raft. The Styrofoam has dimensions 2.00 m x 2.00 m x 0.0900 m. The bottom 0.024 m of the raft is submerged. (a) Draw a force diagram of the system cons
> A 20.0-kg lead mass rests on the bottom of a pool. (a) What is the volume of the lead? (b) What buoyant force acts on the lead? (c) Find the lead’s weight. (d) What is the normal force acting on the lead?
> A table-tennis ball has a diameter of 3.80 cm and average density of 0.0840 g/cm3. What force is required to hold it completely submerged under water?
> Piston ➀ in Figure P9.16 has a diameter of 0.25 in.; piston ➁ has a diameter of 1.5 in. In the absence of friction, determine the force F( necessary to support the 500-lb weight. Figure P9.16:
> A sphygmomanometer is a device used to measure blood pressure, typically consisting of an inflatable cuff and a manometer used to measure air pressure in the cuff. In a mercury sphygmomanometer, blood pressure is related to the difference in heights betw
> Blaise Pascal duplicated Torricelli’s barometer using a red Bordeaux wine, of density 984 kg/m3 as the working liquid (Fig. P9.14). (a) What was the height h of the wine column for normal atmospheric pressure? (b) Would you expect the v
> A container is filled to a depth of 20.0 cm with water. On top of the water floats a 30.0-cm-thick layer of oil with specific gravity 0.700. What is the absolute pressure at the bottom of the container?
> A hydraulic jack has an input piston of area 0.050 m2 and an output piston of area 0.70 m2. How much force on the input piston is required to lift a car weighing 1.2 x 104 N?
> A collapsible plastic bag (Fig. P9.11) contains a glucose solution. If the average gauge pressure in the vein is 1.33 x 103 Pa, what must be the minimum height h of the bag to infuse glucose into the vein? Assume the specific gravity of the solution is 1
> If you are asked to make a very sensitive glass thermometer, which of the following working fluids would you choose? (a) Mercury (b) Alcohol (c) Gasoline (d) Glycerin
> (a) Calculate the absolute pressure at the bottom of a freshwater lake at a depth of 27.5 m. Assume the density of the water is 1.00 x 103 kg/m3 and the air above is at a pressure of 101.3 kPa. (b) What force is exerted by the water on the window of an u
> A normal blood pressure reading is less than 120/80 where both numbers are gauge pressures measured in millimeters of mercury (mmHg). What are the (a) Absolute and (b) Gauge pressures in pascals at the base of a 0.120 m column of mercury?
> Suppose a distant world with surface gravity of 7.44 m/s2 has an atmospheric pressure of 8.04 x 104 Pa at the surface. (a) What force is exerted by the atmosphere on a disk-shaped region 2.00 m in radius at the surface of a methane ocean? (b) What is the
> The four tires of an automobile are inflated to a gauge pressure of 2.0 x 105 Pa. Each tire has an area of 0.024 m2 in contact with the ground. Determine the weight of the automobile.
> The nucleus of an atom can be modeled as several protons and neutrons closely packed together. Each particle has a mass of 1.67 x 10-27 kg and radius on the order of 10-15 m. (a) Use this model and the data provided to estimate the density of the nucleus
> Calculate the mass of a solid gold rectangular bar that has dimensions of 4.50 cm x 11.0 cm x 26.0 cm.
> The weight of Earth’s atmosphere exerts an average pressure of 1.01 x 105 Pa on the ground at sea level. Use the definition of pressure to estimate the weight of Earth’s atmosphere by approximating Earth as a sphere of radius RE = 6.38 x 106 m and surfac
> The British gold sovereign coin is an alloy of gold and copper having a total mass of 7.988 g, and is 22-karat gold. (a) Find the mass of gold in the sovereign in kilograms using the fact that the number of karats = 24 x (mass of gold)/(total mass). (b)
> Mercury is poured into a U-tube as shown in Figure P9.10a. The left arm of the tube has cross-sectional area A1 of 10.0 cm2, and the right arm has a cross-sectional area A2 of 5.00 cm2. One hundred grams of water are then poured into the right arm as sho
> An 81.5-kg man stands on a horizontal surface. (a) What is the volume of the man’s body if his average density is 985 kg/m3? (b) What average pressure from his weight is exerted on the horizontal surface if the man’s two feet have a combined area of 4.50
> If you quickly plunge a room-temperature mercury thermometer into very hot water, the mercury level will (a) Go up briefly before reaching a final reading, (b) Go down briefly before reaching a final reading, or (c) Not change.
> A typical propeller of a turbine used to generate electricity from the wind consists of three blades as in Figure P8.75. Each blade has a length of L = 35 m and a mass of m = 420 kg. The propeller rotates at the rate of 25 rev/min. (a) Convert the angula
> A particle of mass 0.400 kg is attached to the 100-cm mark of a meter stick of mass 0.100 kg. The meter stick rotates on a horizontal, frictionless table with an angular speed of 4.00 rad/s. Calculate the angular momentum of the system when the stick is
> A cylinder with moment of inertia I1 rotates with angular velocity ω0 about a frictionless vertical axle. A second cylinder, with moment of inertia I2, initially not rotating, drops onto the first cylinder (Fig. P8.73). Because the surfaces ar
> A space station shaped like a giant wheel has a radius of 100 m and a moment of inertia of 5.00 x 108 kg · m2. A crew of 150 lives on the rim, and the station is rotating so that the crew experiences an apparent acceleration of 1g (Fig. P8.
> The puck in Figure P8.71 has a mass of 0.120 kg. Its original distance from the center of rotation is 40.0 cm, and it moves with a speed of 80.0 cm/s. The string is pulled downward 15.0 cm through the hole in the frictionless table. Determine the work do
> A student sits on a rotating stool holding two 3.0-kg objects. When his arms are extended horizontally, the objects are 1.0 m from the axis of rotation and he rotates with an angular speed of 0.75 rad/s. The moment of inertia of the student plus stool is
> A solid, horizontal cylinder of mass 10.0 kg and radius 1.00 m rotates with an angular speed of 7.00 rad/s about a fixed vertical axis through its center. A 0.250-kg piece of putty is dropped vertically onto the cylinder at a point 0.900 m from the cente
> A 60.0-kg woman stands at the rim of a horizontal turntable having a moment of inertia of 500 kg · m2 and a radius of 2.00 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. The woman then
> A student holds a spinning bicycle wheel while sitting motionless on a stool that is free to rotate about a vertical axis through its center (Fig. P8.67). The wheel spins with an angular speed of 17.5 rad/s and its initial angular momentum is directed up
> Halley’s comet moves about the Sun in an elliptical orbit, with its closest approach to the Sun being 0.59 AU and its greatest distance being 35 AU (1 AU is the Earth–Sun distance). If the comet’s speed at closest approach is 54 km/s, what is its speed w
> Two objects with different sizes, masses, and temperatures are placed in thermal contact. Choose the best answer: Energy travels (a) From the larger object to the smaller object (b) From the object with more mass to the one with less mass (c) From the ob
> A light rigid rod of length â„“ = 1.00 m rotates about an axis perpendicular to its length and through its center, as shown in Figure P8.51. Two particles of masses m1 = 4.00 kg and m2 = 3.00 kg are connected to the ends of the rod. What
> A 0.005 00-kg bullet traveling horizontally with a speed of 1.00 x 103 m/s enters an 18.0-kg door, embedding itself 10.0 cm from the side opposite the hinges as in Figure P8.64. The 1.00-m-wide door is free to swing on its hinges. (a) Before it hits the
> (a) Calculate the angular momentum of Earth that arises from its spinning motion on its axis, treating Earth as a uniform solid sphere. (b) Calculate the angular momentum of Earth that arises from its orbital motion about the Sun, treating Earth as a poi
> A disk of mass m is spinning freely at 6.00 rad/s when a second identical disk, initially not spinning, is dropped onto it so that their axes coincide. In a short time the two disks are corotating. (a) What is the angular speed of the new system? (b) If
> A metal hoop lies on a horizontal table, free to rotate about a fixed vertical axis through its center while a constant tangential force applied to its edge exerts a torque of magnitude 1.25 x 10-2 N · m for 2.00 s. (a) Calculate the magnitude of the hoo
> A 3.2-kg sphere is suspended by a cord that passes over a 1.8-kg pulley of radius 3.8 cm. The cord is attached to a spring whose force constant is k = 86 N/m as in Figure P8.95. Assume the pulley is a solid disk. (a) If the sphere is released from rest w
> A 10.0-kg monkey climbs a uniform ladder with weight w = 1.20 x 102 N and length L = 3.00 m as shown in Figure P8.94. The ladder rests against the wall at an angle of θ = 60.0°. The upper and lower ends of the ladder rest on frict
> An object of mass m1 = 4.00 kg is connected by a light cord to an object of mass m2 = 3.00 kg on a frictionless surface (Fig. P8.93). The pulley rotates about a frictionless axle and has a moment of inertia of 0.500 kg · m2 and a radius of
> In an emergency situation, a person with a broken forearm ties a strap from his hand to clip on his shoulder as in Figure P8.92. His 1.60-kg forearm remains in a horizontal position and the strap makes an angle of θ = 50.0° with t
> The Iron Cross When a gymnast weighing 750 N executes the iron cross as in Figure P8.91a, the primary muscles involved in supporting this position are the latissimus dorsi (“lats”) and the pectoralis major (â
> The density of lead is greater than iron, and both metals are denser than water. Is the buoyant force on a solid lead object (a) Greater than, (b) Equal to, or (c) Less than the buoyant force acting on a solid iron object of the same dimensions.
> A string is wrapped around a uniform cylinder of mass M and radius R. The cylinder is released from rest with the string vertical and its top end tied to a fixed bar (Fig. P8.90). Show that (a) The tension in the string is one-third the weight of the cyl
> A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in Figure P8.89. Model it as a stiff rod of negligible mass 3.00 m long and joini
> A painter climbs a ladder leaning against a smooth wall. At a certain height, the ladder is on the verge of slipping. (a) Explain why the force exerted by the vertical wall on the ladder is horizontal. (b) If the ladder of length L leans at an angle θ wi
> A uniform solid cylinder of mass M and radius R rotates on a frictionless horizontal axle (Fig. P8.87). Two objects with equal masses m hang from light cords wrapped around the cylinder. If the system is released from rest, find (a) The tension in each c
> A uniform thin rod of length L and mass M is free to rotate on a frictionless pin passing through one end (Fig. P8.47). The rod is released from rest in the horizontal position. (a) What is the speed of its center of gravity when the rod reaches its lowe
> Many aspects of a gymnast’s motion can be modeled by representing the gymnast by four segments consisting of arms, torso (including the head), thighs, and lower legs, as in Figure P8.85. Figure P8.85b shows arrows of lengths rcg locatin
> A light rod of length 2L is free to rotate in a vertical plane about a frictionless pivot through its center. A particle of mass m1 is attached at one end of the rod, and a mass m2 is at the opposite end, where m1 > m2. The system is released from res
> A 2.35-kg uniform bar of length â„“ = 1.30 m is held in a horizontal position by three vertical springs as in Figure P8.83. The two lower springs are compressed and exert upward forces on the bar of magnitude F1 = 6.80 N and F2 = 9.50 N,
> Two window washers, Bob and Joe, are on a 3.00-m-long, 345-N scaffold supported by two cables attached to its ends. Bob weighs 750 N and stands 1.00 m from the left end, as shown in Figure P8.82. Two meters from the left end is the 500-N washing equipmen
