(a) What would the net charges on the Sun and Earth have to be if the electric force instead of the gravitational force were responsible for keeping Earth in its orbit? There are many possible answers, so restrict yourself to the case where the magnitude of the charges is proportional to the masses. (b) If the magnitude of the charges of the proton and electron were not exactly equal, astronomical bodies would have net charges that are approximately proportional to their masses. Could this possibly be an explanation for Earth’s orbit?
> A steam engine has a piston with a diameter of 15.0 cm and a stroke (the displacement of the piston) of 20.0 cm. The average pressure applied to this piston is 1.3 × 105 Pa. What operating frequency in cycles per second (Hz) would yield an average power
> An air conditioner whose coefficient of performance is 2.00 removes 1.73 × 108 J of heat from a room per day. How much does it cost to run the air conditioning unit per day if electricity costs $0.10 per kilowatt-hour? (Note that 1 kilowatt-hour = 3.6 ×
> A house with its own well has a pump in the basement with an output pipe of inner radius 6.3 mm. The pump can maintain a gauge pressure of 410 kPa in the output pipe. A showerhead on the second floor (6.7 m above the pump’s output pipe) has 36 holes, eac
> Emil is tossing an orange of mass 0.30 kg into the air. (a) Emil throws the orange straight up and then catches it, throwing and catching it at the same point in space. What is the change in the potential energy of the orange during its trajectory? Igno
> How much heat does a heat pump with a coefficient of performance of 3.0 deliver when supplied with 1.00 kJ of electricity?
> An engine releases 0.450 kJ of heat for every 0.100 kJ of work it does. What is the efficiency of the engine?
> The intensity (power per unit area) of the sunlight incident on Earth's surface, averaged over a 24 h period, is about 0.20 kW/m2. If a solar power plant is to be built with an output capacity of 1.0 × 109 W, how big must the area of the solar energy col
> The United States generates about 5.0 × 1016 J of electric energy a day. This energy is equivalent to work, since it can be converted into work with almost 100% efficiency by an electric motor. (a) If this energy is generated by power plants with an ave
> A heat pump delivers heat at a rate of 7.81 kW for 10.0 h. If its coefficient of performance is 6.85, how much heat is taken from the cold reservoir during that time?
> What is the efficiency of an electric generator that produces 1.17 kW·h per kilogram of coal burned? The heat of combustion of coal is 6.71 × 106 J/kg.
> Using the stress-strain graph for bone (Fig. 10.4c), calculate Young’s moduli for tension and for compression. Consider only small stresses.
> A surgeon is attempting to correct a detached retina by using a pulsed laser. (a) If the pulses last for 20.0 ms and if the output power of the laser is 0.500 W, how much energy is in each pulse? (b) If the wavelength of the laser light is 643 nm, how
> An object located at the origin and having mass M explodes into three pieces having masses M/4, M/3, and 5M/12. The pieces scatter on a horizontal frictionless xy-plane. The piece with mass M/4 flies away with velocity 5.0 m/s at 37° above the x-axis. Th
> Repeat Problem 51(a), this time assuming the electron is ultra- relativistic (E ≈ pc). Is the assumption justified?
> A heat engine follows the cycle shown in the figure. (a) How much net work is done by the engine in one cycle? (b) What is the net heat flow into the engine per cycle?
> If an electron moves from one point at a potential of −100.0 V to another point at a potential of +100.0 V, how much work is done by the electric field?
> (a) Which might describe a heat engine? (b) Which might describe a heat pump? (c) Which might describe a refrigerator? Explain.
> An airline executive decides to economize by reducing the amount of fuel required for long-distance flights. He orders the ground crew to remove the paint from the outer surface of each plane. The paint removed from a single plane has a mass of approxima
> Rank the processes in order of the net work done by the system per cycle, from greatest to least. Rank positive work done by the system (as in an engine) higher than negative work done by the system (as in a heat pump).
> Suppose 1.00 mol of oxygen is heated at constant pressure of 1.00 atm from 10.0°C to 25.0°C. (a) How much heat is absorbed by the gas? (b) Using the ideal gas law, calculate the change of volume of the gas in this process. (c) What is the work done by
> An ideal gas is in contact with a heat reservoir so that it remains at a constant temperature of 300.0 K. The gas is compressed from a volume of 24.0 L to a volume of 14.0 L. During the process, the mechanical device pushing the piston to compress the ga
> A transverse wave on a string is described by where A = 0.40 mm, ω = 39.27 rad/s, and k = 6.0 rad/m. Draw a motion diagram for the point x = 0 for the times t = 0, 0.010 s, 0, 0.020 s, 0.030 s, and 0.040 s.
> If the pressure on a fish increases from 1.1 atm to 1.2 atm, its swim bladder decreases in volume from 8.16 mL to 7.48 mL while the temperature of the air inside remains constant. How much work is done on the air in the bladder?
> On a graph of ax versus time, what quantity does the area under the graph represent?
> An ideal gas is heated at a constant pressure of 2.0 × 105 Pa from a temperature of −73°C to a temperature of +27°C. The initial volume of the gas is 0.10 m3. The heat energy supplied to the gas in this process is 25 kJ. What is the increase in internal
> A balloon contains 200.0 L of nitrogen gas at 20.0°C and at atmospheric pressure. How much energy must be added to raise the temperature of the nitrogen to 40.0°C while allowing the balloon to expand at atmospheric pressure?
> In a refrigerator, 2.00 mol of an ideal monatomic gas are taken through the cycle shown in the figure. The temperature at point A is 800.0 K. (a) What are the temperature and pressure at point D? (b) What is the net work done on the gas as it is taken
> The three processes shown with Multiple Choice Question 8 involve a diatomic ideal gas. Rank them in order of the change in internal energy, from greatest to smallest.
> (a) Find the equivalent resistance between points A and B for the combination of resistors shown. (b) An 18 V emf is connected to the terminals A and B. What is the current through the 1.0 Ω resistor connected directly to point A? (
> The beam emerging from a ruby laser passes through a circular aperture 5.0 mm in diameter. (a) If the spread of the beam is limited only by diffraction, what is the angular spread of the beam? (b) If the beam is aimed at the Moon, how large a spot would
> Copper and aluminum are being considered for the cables in a high- voltage transmission line where each must carry a current of 50 A. The resistance of each cable is to be 0.15 Ω per kilometer. (a) If this line carries power from Niagara Falls to New Yo
> Brad tries out a weight-loss plan that involves repeatedly lifting a 50.0 kg barbell from the floor over his head to a height of 2.0 m. If he is able to complete three such lifts per minute, how long will it take for him to lose 0.50 kg of fat? “Burning”
> Some forms of cancer can be treated using proton therapy in which proton beams are accelerated to high energies, then directed to collide into a tumor, killing the malignant cells. Suppose a proton accelerator is 4.0 m long and must accelerate protons fr
> Find the work done by gravity on the sliding crate.
> An ideal monatomic gas is taken through the cycle in the PV diagram. (a) If there are 0.0200 mol of this gas, what are the temperature and pressure at point C? (b) What is the change in internal energy of the gas as it is taken from A to B? (c) How muc
> On a graph of vx versus time, what quantity does the slope of the graph represent?
> On a cold day, Ming rubs her hands together to warm them up. She presses her hands together with a force of 5.0 N. Each time she rubs them back and forth, they move a distance of 16 cm with a coefficient of kinetic friction of 0.45. Assuming no heat flow
> During basketball practice Shane made a jump shot, releasing a 0.60 kg basketball from his hands at a height of 2.0 m above the floor with a speed of 7.6 m/s. The ball swooshes through the net at a height of 3.0 m above the floor and with a speed of 4.5
> A 64 kg sky diver jumped out of an airplane at an altitude of 0.90 km. She opened her parachute after a while and eventually landed on the ground with a speed of 5.8 m/s. How much energy was dissipated by air resistance during the jump?
> A child of mass 15 kg climbs to the top of a slide that is 1.7 m above a horizontal run that extends for 0.50 m at the base of the slide. After sliding down, the child comes to rest just before reaching the very end of the horizontal portion of the slide
> In a physics lab, a student accidentally drops a 25.0 g brass washer into an open dewar of liquid nitrogen at 77.2 K. How much liquid nitrogen boils away as the washer cools from 293 K to 77.2 K? The latent heat of vaporization for nitrogen is 199.1 kJ/k
> Charges of −12.0 nC and −22.0 nC are separated by 0.700 m. What is the potential midway between the two charges?
> What is the maximum possible torque on the molecule due to the electric field?
> In an RLC series circuit, these three elements are connected in series: a resistor of 60.0 Ω, a 40.0 mH inductor, and a 0.0500 F capacitor. The series elements are connected across the terminals of an ac oscillator with an rms voltage of 10.0 V. Find the
> In an emergency, it is sometimes the practice of medical professionals to immerse a patient who suffers from heat stroke in an ice bath, a mixture of ice and water in equilibrium at 0°C, in order to reduce her body temperature. (a) If a 75 kg patient wh
> As heat flows into a substance, its temperature changes according to the graph in the diagram. For which sections of the graph is the substance undergoing a phase change? For the sections you identified, what kind of phase change is occurring?
> A chamber with a fixed volume of 1.0 m3 contains a monatomic gas at 3.00 × 102 K. The chamber is heated to a temperature of 4.00 × 102 K. This operation requires 10.0 J of heat. (Assume all the energy is transferred to the gas.) How many gas molecules ar
> A 200.0 µF capacitor is placed across a 12.0 V battery. When a switch is thrown, the battery is removed from the capacitor and the capacitor is connected across a heater that is immersed in 1.00 cm3 of water. Assuming that all the energy from the capacit
> What is the de Broglie wavelength of an electron with kinetic energy 7.0 TeV?
> Jill takes in 0.021 mol of air in a single breath. The air is taken in at 20°C and exhaled at 35°C. (a) How much heat leaves her body in a single breath due to the temperature increase of the air? Ignore the humidification of the air in the lungs and tre
> Consider two falling objects. Their masses are 3.0 kg and 4.0 kg. At time t = 0, the two are released from rest. What is the velocity of their CM at t = 10.0 s? Ignore air resistance.
> A muon decay is described by . What is the maximum kinetic energy of the electron, if the muon was at rest? Assume that the electron is extremely relativistic and ignore the small masses of the neutrinos.
> Imagine that 501 people are present in a movie theater of volume 8.00 × 103 m3 that is sealed shut so no air can escape. Each person gives off heat at an average rate of 110 W. By how much will the temperature of the air have increased during a 2.0 h mov
> A Foucault pendulum has an object with a mass of 15.0 kg hung by a thin 14.0 m wire. (a) What is the oscillation frequency of this pendulum? (b) If the pendulum has a maximum oscillation angle of 6.10°, what is the maximum speed of this pendulum? (c)
> A heating coil inside an electric kettle delivers 2.1 kW of electric power to the water in the kettle. How long will it take to raise the temperature of 0.50 kg of water from 20.0°C to 100.0°C?
> A 24 V emf is connected to terminals A and B in the following circuit. Find the current in each of the resistors.
> A 7.30 kg steel ball at 15.2°C is dropped from a height of 10.0 m into an insulated container with 4.50 L of water at 10.1°C. If no water splashes, what is the final temperature of the water and steel?
> A bit of space debris penetrates the hull of a spaceship traversing the asteroid belt and comes to rest in a container of water that was at 20.0°C before being hit. The mass of the debris is 1.0 g and the mass of the water is 1.0 kg. If the space rock tr
> Why do we not notice the effects of 1014 neutrinos passing through our bodies every second?
> A thermometer containing 0.10 g of mercury is cooled from 15.0°C to 8.5°C. How much energy left the mercury in this process?
> It is a damp, chilly day in a New England seacoast town suffering from a power failure. To warm up the cold, clammy sheets, Jen decides to fill hot water bottles to tuck between the sheets at the foot of the beds. If she wishes to heat 2.0 L of water on
> An experiment is conducted with a Joule apparatus (see Fig. 14.2). The hanging objects descend through a distance of 1.25 m each time. After 30 descents, a total of 1.00 kJ has been delivered to the water. What is the total mass of the hanging objects?
> Rank the points in order of mechanical energy, from greatest to least, taking friction and air resistance into consideration.
> A scanning electron microscope is used to look at cell structure with 10 nm resolution. A beam of electrons from a hot filament is accelerated with a voltage of 12 kV and then focused to a small spot on the specimen. (a) What is the wavelength in nanome
> A series RLC circuit has R = 500.0 Ω, L = 35.0 mH, and C = 87.0 pF. What is the impedance of the circuit at resonance? Explain.
> The water passing over Victoria Falls, located along the Zambezi River on the border of Zimbabwe and Zambia, drops about 105 m. How much internal energy is produced per kilogram as a result of the fall?
> A mass of 1.00 kg of water at temperature T is poured from a height of 0.100 km into a vessel containing water of the same temperature T, and a temperature change of 0.100°C is measured. What mass of water was in the vessel? Ignore heat flow into the ves
> It takes 880 J to raise the temperature of 350 g of lead from 0°C to 20.0°C. What is the specific heat of lead?
> What is the period of oscillation for small amplitudes?
> (a) Given two identical, ideal batteries (/ ) and two identical incandescent lightbulbs (resistance = R assumed constant), design a circuit to make both bulbs glow as brightly as possible. (b) What is the power dissipated by each bulb? (c) Design a c
> Describe the use of “color” as a quantum number for the quarks.
> What is the heat capacity of a system consisting of (a) a 0.450 kg brass cup filled with 0.050 kg of water? (b) 7.5 kg of water in a 0.75 kg aluminum bucket?
> Rank these six situations in order of the temperature increase, largest to smallest. (a) 1 kJ of heat into 400 g of steel with c = 0.45 kJ/(kg·K) (b) 2 kJ of heat into 400 g of steel (c) 2 kJ of heat into 800 g of steel (d) 1 kJ of heat into 400 g of alu
> If 125.6 kJ of heat are supplied to 5.00 × 102 g of water at 22°C, what is the final temperature of the water?
> Convert 1.00 kJ to kilowatt-hours (kWh).
> Show that 1 kilowatt-hour (kW·h) is equal to 3.6 MJ.
> In a tornado or hurricane, a roof may tear away from the house because of a difference in pressure between the air inside and the air outside. Suppose that air is blowing across the top of a 2000 ft2 roof at 150 mi/h. What is the magnitude of the force o
> A nozzle of inner radius 1.00 mm is connected to a hose of inner radius 8.00 mm. The nozzle shoots out water moving at 25.0 m/s. (a) At what speed is the water in the hose moving? (b) What is the volume flow rate? (c) What is the mass flow rate?
> A meson with charge −e composed of up and/or down quarks and/or antiquarks.
> An object of mass 2.0 kg (the “projectile”) approaches a stationary object (the “target”) at 8.0 m/s. The projectile is deflected through an angle of 90.0° and its speed after the collision is 6.0 m/s. What is the speed of the target after the collision
> If the average volume flow of blood through the aorta is 8.5 × 10−5 m3/s and the cross-sectional area of the aorta is 3.0 × 10−4 m2, what is the average speed of blood in the aorta?
> A 0.15 kg baseball is pitched with a speed of 35 m/s (78 mi/h). When the ball hits the catcher's glove, the glove moves back by 5.0 cm (2 in.) as it stops the ball. (a) What was the change in momentum of the baseball? (b) What impulse was applied to th
> A garden hose of inner radius 1.0 cm carries water at 2.0 m/s. The nozzle at the end has inner radius 0.20 cm. How fast does the water move through the nozzle?
> A stationary 0.1 g fly encounters the windshield of a 1000 kg automobile traveling at 100 km/h. (a) What is the change in momentum of the car due to the fly? (b) What is the change of momentum of the fly due to the car? (c) Approximately how many flie
> A piece of metal is released under water. The volume of the metal is 50.0 cm3 and its specific gravity is 5.0. What is its initial acceleration?
> If a car (mass 1200 kg) traveling at 28 m/s is brought to a full stop in 4.0 s after the brakes are applied, find the average frictional force exerted on the car.
> An inexperienced catcher catches a 130 km/h fastball of mass 140 g within 1 ms, whereas an experienced catcher slightly retracts his hand during the catch, extending the stopping time to 10 ms. What are the average forces imparted to the two gloved hands
> A stone used to grind wheat into flour is turned through 12 revolutions by a constant force of 20.0 N applied to the rim of a 10.0 cm radius shaft connected to the wheel. How much work is done on the stone during the 12 revolutions?
> When photons with a wavelength of 120.0 nm are incident on a metal, electrons are ejected that can be stopped with a stopping potential of 6.00 V. (a) What stopping potential is needed when the photons have a wavelength of 240.0 nm? (b) What happens wh
> (a) A piece of balsa wood with density 0.50 g/cm3 is released under water. What is its initial acceleration? (b) Repeat for a piece of maple with density 0.750 g/cm3. (c) Repeat for a ping-pong ball with an average density of 0.125 g/cm3.
> In the circuit and R = 100.0 Ω. Assume the emf is ideal. If a voltage Vx = 30.0 V is needed for a circuit, what should resistance Rx be?
> A helicopter is flying horizontally at 8.0 m/s and an altitude of 18 m when a package of emergency medical supplies is ejected horizontally backward with a speed of 12 m/s relative to the helicopter. Ignoring air resistance, what is the horizontal distan
> To contain a violent mob, the riot squad approaches with fire hoses. Suppose that the rate of flow of water through a fire hose is 24 kg/s, and the stream of water from the hose moves at 17 m/s. What force is exerted by such a stream on a person in the c
> On a kitchen scale you measure the coin’s mass to be 49.7 g. You measure the mass of a small bowl of water as 314.8 g. You tie a slender thread around the coin and suspend it completely submerged in the water but not touching the bottom. The scale readin
> A child places 12 wooden blocks together, as shown in the figure. If each block has the same mass and density, where is the CM of these blocks? Each block is a cube with sides of 1.0 inch length. The origin of the coordinate system is at the center of th
> You suspend the coin from a spring scale and find that its mass is 49.7 g. You then let the coin hang completely submerged in a glass of water but not touching the bottom and find that the scale reads 47.1 g. Should you get excited about the possibility
> A uniform rod of length 30.0 cm is bent into the shape of an inverted U. Each of the three sides is of length 10.0 cm. Find the location, in x- and y-coordinates, of the CM as measured from the origin.
> The average density of a fish can be found by first weighing it in air and then finding the scale reading for the fish completely immersed in water and suspended from a scale. If a fish has weight 200.0 N in air and scale reading 15.0 N in water, what is
> An intergalactic spaceship is traveling through space far from any planets or stars, where no human has gone before. The ship carries a crew of 30 people (of total mass 2.0 × 103 kg). If the speed of the spaceship is 1.0 × 105 m/s and its mass (excluding
> A pilot without special training or equipment can tolerate a horizontal acceleration of up to about 9g for a short period of time (about a minute) without losing consciousness. (a) How long would it take a supersonic jet in horizontal flight to accelera
