All Matches
Solution Library
Expert Answer
Textbooks
Search Textbook questions, tutors and Books
Oops, something went wrong!
Change your search query and then try again
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
physics
mechanics
Questions and Answers of
Mechanics
Consider the air-conditioning system described in Problem 59.(a) Does the entropy of the universe increase, decrease, or stay the same as the air conditioner keeps the imperfectly insulated house
A heat engine operates between a high-temperature reservoir at 610 K and a low-temperature reservoir at 320 K. In one cycle, the engine absorbs 6400 J of heat from the high-temperature reservoir and
It can be shown that as a mass m with specific heat c changes temperature from T i to T f its change in entropy is Δ S = mcln (Tf/Ti) if the temperatures are expressed in kelvin. Suppose you put 79
Consider the three-process cycle shown in FIGURE 18- 33. For each process in the cycle,(a) A → B,(b) B → C,(c) C → A, state whether the work done by the system is positive,
An ideal gas has the pressure and volume indicated by point I in FIGURE 18-34. At this point its temperature is T1. The temperature of the gas can be increased to T2 by using the constant-volume
The heat that goes into a particular Carnot engine is 4.00 times greater than the work it performs. What is the engine's efficiency?
Consider 132 moles of a monatomic gas undergoing the isothermal expansion shown in Figure 18-28.(a) What is the temperature T of this expansion?(b) Does the entropy of the gas increase, decrease, or
A hot-air balloon is inflated by heating air at constant pressure. Assume the number of air molecules inside the balloon remains constant and that it expands at atmospheric pressure.(a) If the
Referring to Figure 18-31, suppose 60.0 moles of a monatomic ideal gas are expanded along process 5.(a) How much work does the gas do during this expansion?(b) What is the change in the internal
Engine A has an efficiency of 66%. Engine B absorbs the same amount of heat from the hot reservoir and exhausts twice as much heat to the cold reservoir.(a) Which engine has the greater efficiency?
One mole of an ideal monatomic gas is initially at a temperature of 274 K.(a) Find the final temperature of the gas if 3260 J of heat are added to it and it does 712 J of work.(b) Suppose the amount
Because of safety concerns and other constraints, nuclear power plants must be run at lower efficiencies than natural gas-fired power plants. The efficiency of a particular gas-fired power plant is
A freezer with a coefficient of performance of 3.88 is used to convert 1.75 kg of water to ice in one hour. The water starts at a temperature of 20.0 °C, and the ice that is produced is cooled to a
The surface of the Sun has a temperature of 5500 °C and the temperature of deep space is 3.0 K. (a) Find the entropy increase produced by the Sun in one day, given that it radiates heat at the rate
The following table lists results for various processes involving n moles of a monatomic ideal gas. Fill in the missing entries.
A cylinder with a movable piston holds 2.95 mol of argon at a constant temperature of 235 K. As the gas is compressed isothermally, its pressure increases from 101 kPa to 121 kPa. Find (a) The final
You place 0.410 kg of cold water inside a freezer that has a constant temperature of 0 °C. The water eventually freezes and becomes ice at 0 °C.(a) What is the change in entropy of the water
An inventor claims a new cyclic engine that uses organic grape juice as its working material. According to the claims, the engine absorbs 1250 J of heat from a 1010 K reservoir and performs 1120 J of
A small dish containing 530 g of water is placed outside for the birds. During the night the outside temperature drops to -5.0 °C and stays at that value for several hours. (a) When the water in the
An ideal gas is taken through the three processes shown in Figure 18-25. Fill in the missing entries in the following table.Figure 18-25
One mole of an ideal monatomic gas follows the three-part cycle shown in FIGURE 18-35.(a) Fill in the table below.(b) What is the efficiency of this cycle?Figure 18-35
Burning a gallon of gasoline releases 1.19 × 108 J of internal energy. If a certain car requires 5.20 × 105 J of work to drive one mile,(a) How much heat is given off to the atmosphere each mile,
When a heat Q is added to a monatomic ideal gas at constant pressure, the gas does a work W. Find the ratio, W/Q.
FIGURE 18-36 shows an example of a Carnot cycle. The cycle consists of the following four processes: (1) an isothermal expansion from V1 to V2 at the temperature Th; (2) an adiabatic expansion from
A Carnot engine and a Carnot refrigerator operate between the same two temperatures. Show that the coefficient of performance, COP, for the refrigerator is related to the efficiency, e, of the engine
Suppose an OTEC system operates with surface water at 22 °C and deep water at 4.0 °C. What is the maximum efficiency this system could have? A. 6.10% B. 8.20% C. 9.40% D. 18.0%
If we could go deeper for colder water, say to a depth of 4500 m, what is the maximum efficiency that can be achieved? A. 6.64% B. 7.52% C. 14.0% D. 25.5%
After they are used in the OTEC plant, the warm surface water and cold deep water (which is richer in inorganic nutrients) may be mixed together and discharged back into the ocean. In this process,
A commercial OTEC system may take in 1500 kg of water per second at 22 °C and cool it to 4.0 °C. How much energy is released in one second by this system? (For comparison, the energy released in
Suppose we lower the temperature of the cold reservoir to 295 K; the temperature of the hot reservoir is still 576 K. (a) Is the new efficiency of the engine greater than, less than, or equal to
Suppose the temperature of the hot reservoir is increased by 16 K, from 576 K to 592 K, and that the temperature of the cold reservoir is also increased by 16 K, from 305 K to 321 K.(a) Is the new
1. A student's weight displayed on a digital scale is 117.2 lb.This would suggest her weight is(a) Within 1% of 117.2 lb.(b) Exactly 117.2 lb.(c) Somewhere between 117.18 and 117.22 lb.(d) Somewhere
1. A student's weight displayed on a digital scale is 117.2 lb. This would suggest her weight is (a) Within 1% of 117.2 lb. (b) Exactly 117.2 lb. (c) Somewhere between 117.18 and 117.22 lb. (d)
1. Accuracy represents (a) Repeatability of a measurement, using a given instrument. (b) How close a measurement is to the true value. (c) An ideal number of measurements to make. (d) How poorly an
1. How many significant figures do each of the following numbers have: (a) 214, (b) 81.60, (c) 7.03, (d) 0.03, (e) 0.0086, (f ) 3236, and (g) 8700?
What, roughly, is the percent uncertainty in the volume of a spherical beach ball of radius r = 0.84 ± 0.04m?
What is the area, and its approximate uncertainty, of a circle of radius 3.1 × 104 cm?
Write the following as full (decimal) numbers without prefixes on the units:(a) 286.6 mm,(b) 85 μV,(c) 760 mg,(d) 62.1 ps,(e) 22.5 nm,(f) 2.50 gigavolts.
Express the following using the prefixes of Table 1-4:(a) 1 × 106 volts,(b) 2 × 10-6 meters,(c) 6 × 103 days,(d) 18 × 102 bucks,(e) 7 × 10-7 seconds.
Write the following numbers in powers of 10 notations: (a) 1.156, (b) 21.8, (c) 0.0068, (d) 328.65, (e) 0.219, (f) 444.
American football uses a field that is 100.0 yd long, whereas a soccer field is 100.0 m long. Which field is longer, and by how much (give yards, meters, and percent)?
A standard baseball has a circumference of approximately 23 cm. If a baseball had the same mass per unit volume (see Tables in Section 1-5) as a neutron or a proton, about what would its mass be?
I agree to hire you for 30 days. You can decide between two methods of payment: either(1) $1000 a day, or(2) One penny on the first day, two pennies on the second day and continue to double your
The smallest meaningful measure of length is called the Planck length, and is defined in terms of three fundamental constants in nature: the speed of light c = 300 × 108 m / s, the gravitational
Computer chips (Fig. 1-17) are etched on circular silicon wafers of thickness 0.300 mm that are sliced from a solid cylindrical silicon crystal of length 25 cm. If each wafer can hold 400 chips, what
If you used only a keyboard to enter data, how many years would it take to fill up the hard drive in a computer that can store 1.0 terabytes (1.0 × 1012bytes) of data? Assume 40-hour work weeks, and
A certain compact disc (CD) contains 783.216 megabytes of digital information. Each byte consists of exactly 8 bits. When played, a CD player reads the CD's information at a constant rate of 1.4
Estimate how many days it would take to walk around the Earth, assuming 12 h walking per day at 4 km / h.
One mole of atoms consists of 6.02 × 1023 individual atoms. If a mole of atoms were spread uniformly over the Earth's surface, how many atoms would there be per square meter?
Time intervals measured with a stopwatch typically have an uncertainty of about 0.2 s, due to human reaction time at the start and stop moments. What is the percent uncertainty of a hand-timed
The density of an object is defined as its mass divided by its volume. Suppose a rock's mass and volumes are measured to be 6 g and 2.8325 cm3. To the correct number of significant figures, determine
Recent findings in astrophysics suggest that the observable universe can be modeled as a sphere of radius R = 13.7 × 109 light-years = 13.0 × 1025 m with an average total mass density of about 1 ×
Multiply 3.079 × 102m by 0.068 × 10-1 m, taking into account significant figures.
1. Which of the following should be part of solving any problem in physics? Select all that apply: (a) Read the problem carefully. (b) Draw a picture of the situation. (c) Write down the variables
1. You drop a rock off a bridge. When the rock has fallen 4m, you drop a second rock. As the two rocks continue to fall, what happens to their velocities? (a) Both increase at the same rate. (b) The
A car travels along the x axis with increasing speed. We don't know if to the left or the right. Which of the graphs in Fig. 2-34 most closely represents the motion of the car?(a)(b) (c) (d) (e)
If you are driving 95km / h along a straight road and you look to the side for 2.0 s, how far do you travel during this inattentive period?
A car traveling is 210 m behind a truck traveling 95 km /h is 210 m behind a truck traveling 75 km/h. How long will it take the car to reach the truck?
Two locomotives approach each other on parallel tracks. Each has a speed of 155 km/h with respect to the ground. If they are initially 8.5 km apart, how long will it be before they reach each other?
Digital bits on a 12.0-cm diameter audio CD are encoded along an outward spiraling path that starts at radius R1 = 2.5 cm and finishes at radius R2 = 5.8cm. The distance between the centers of
A bowling ball traveling with constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting the pins 2.80 s after the ball is released from his
An automobile traveling 95 km/h overtakes a 1.30-kmlong train traveling in the same direction on a track parallel to the road. If the train's speed is 75 km/h, how long does it take the car to pass
A sports car accelerates from rest to 95 km / h in 4.3 s. What is its average acceleration in m / s2?
A sprinter accelerates from rest to 9.00 m / s in 1.38 s. What is her acceleration in (a) m / s2; (b) km / h2?
A sports car moving at constant velocity travels 120m in 5.0 s. If it then brakes and comes to a stop in 4.0 s, what is the magnitude of its acceleration (assumed constant) in m / s2, and in g's (g =
What must your car's average speed be in order to travel 235 km in 2.75 h?
At highway speeds, a particular automobile is capable of an acceleration of about 1.8 m/s2. At this rate, how long does it take to accelerate from 65 km/h to 120 km/h?
A car moving in a straight line starts at x = 0 at t = 0. It passes the point x = 25.0 m with a speed of 11.0 m / s at t = 3.00 s. it passes the point x = 385 m with a speed of 45.0 m/s at t = 20.0
A car slows down from 28 m / s to rest in a distance of 88 m. What was its acceleration, assumed constant?
A car accelerates from 14 m / s to 21 m / s in 6.0 s. What was its acceleration? How far did it travel in this time? Assume constant acceleration.
A light plane must reach a speed of 35m/s for takeoff. How long a runway is needed if the (constant) acceleration is 3.0 m/s2?
A baseball pitcher throws a baseball with a speed of 43 m/s. Estimate the average acceleration of the ball during the throwing motion. In throwing the baseball, the pitcher accelerates it through a
A world-class sprinter can reach a top speed (of about 11.5m / s) in the first 18.0 m of a race. What is the average acceleration of this sprinter and how long does it take her to reach that speed?
A car slows down uniformly from a speed of 28.0 m / s to rest in 8.00 s. How far did it travel in that time?
A particle at t1 = - 2.0s is at x1 = 4.8 cm and at t1 = 4.5 s is at x2 = 8.5 cm. What is its average velocity over this time interval? Can you calculate its average speed from these data? Why or why
A car traveling 75km / h slows down at a constant 0.50 m / s2 just by "letting up on the gas." Calculate(a) The distance the car coasts before it stops,(b) The time it takes to stop, and(c) The
Determine the stopping distances for an automobile going a constant initial speed of and human reaction time of 0.40 s: (a) For an acceleration a = -3.0 m / s2, (b) For a = -6.0 m / s2.
A driver is traveling 18.0 m/s when she sees a red light ahead. Her car is capable of decelerating at a rate of 3.65 m/s2. If it takes her 0.350 s to get the brakes on and she is 20.0 m from the
A 75-m-long train begins uniform acceleration from rest. The front of the train has a speed of 18 m / s when it passes a railway worker who is standing 180 m from where the front of the train
A space vehicle accelerates uniformly from 85 m / s at t = 0 to 162 m / s at t = 10.0s. How far did it move between t = 2.0 s and t = 6.0s?
Mary and Sally are in a foot race (Fig. 2-39). When Mary is 22 m from the finish line, she has a speed of 4.0 m / s and is 5.0 m. behind Sally, who has a speed of 5.0 m / s. Sally thinks she has an
A rolling ball moves from x1 = 8.4 cm to x2 = - 4.2 cm during the time from t1 = 3.0s to t2 = 6.1s. What is its average velocity over this time interval?
A ball player catches a ball 3.4 s after throwing it vertically upward. With what speed did he throw it, and what height did it reach?
A baseball is hit almost straight up into the air with a speed of 25 m/s. Estimate(a) How high it goes,(b) How long it is in the air.(c) What factors make this an estimate?
The best rebounders in basketball have a vertical leap (that is, the vertical movement of a fixed point on their body) of about 120 cm.(a) What is their initial "launch" speed off the ground?(b) How
A stone is thrown vertically upward with a speed of 24.0 m/s.(a) How fast is it moving when it is at a height of 13.0 m?(b) How much time is required to reach this height?(c) Why are there two
A helicopter is ascending vertically with a speed of 5.40 m / s. At a height of 105 m above the Earth, a package is dropped from the helicopter. How much time does it take for the package to reach
A bird can fly 25 km/h. How long does it take to fly 3.5 km?
Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.83 s after passing his window. Roger's room is on the third floor, 15m above the sidewalk.(a) How
Suppose you adjust your garden hose nozzle for a fast stream of water. You point the nozzle vertically upward at a height of 1.8 m above the ground (Fig. 2-40). When you quickly turn off the nozzle,
A falling stone takes 0.31 s to travel past a window 2.2 m tall (Fig. 2-41). From what height above the top of the window did the stone fall?
A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 3.4 s later. If the speed of sound is 340 m/s, how high is the cliff?
A sports car accelerates approximately as shown in the velocity-time graph of Fig. 2-43. (The short flat spots in the curve represent manual shifting of the gears.) Estimate the car's average
A person jumps out a fourth-story window 18.0 m above a firefighter's safety net. The survivor stretches the net 1.0m before coming to rest, Fig. 2-45.(a) What was the average deceleration
A bicyclist in the Tour de France crests a mountain pass as he moves at15 km / h. AT the bottom, 4.0 km farther, his speed is 65 km / h. Estimate his average acceleration (in m / s2) while riding
An airplane travels 2100 km at a speed of 720 km / h and then encounters a tailwind that boosts its speed to 990 km / h for the next 2800 km. What was the total time for the trip? What was the
A stone is dropped from the roof of a high building. A second stone is dropped 1.30 s later. How far apart are the stones when the second one has reached a speed of 12.0 m / s?
You are driving home from school steadily at 95 km/h for 180 km. It then begins to rain and you slow to 65 km/h. You arrive home after driving 4.5 h.(a) How far is your hometown from school?(b) What
A stone is thrown vertically upward with a speed of 15.5 m / s from the edge of a cliff 75.0 m high (Fig. 2-48).(a) How much later does it reach the bottom of the cliff?(b) What is its speed just
In the design of a rapid transit system, it is necessary to balance the average speed of a train against the distance between station stops. The more stops there are, the slower the train's average
Showing 20700 - 20800
of 21805
First
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
Last