College Physics
2nd Edition
ISBN: 9780134601823
Author: ETKINA, Eugenia, Planinšič, G. (gorazd), Van Heuvelen, Alan
Publisher: Pearson,
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 7, Problem 5P
You lift a 25-kg child 0.80 m, slowly carry him 10 m to the playroom, and finally set him back down 0.80 m onto the playroom floor. What work do you do on the child for each part of the trip and for the whole trip? List your assumptions.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Chapter 7 Solutions
College Physics
Ch. 7 - Review Question 7.1 Assuming that Earths orbit...Ch. 7 - Review Question 7.2 A system can possess energy...Ch. 7 - Review Question 7.3 When we use the work-energy...Ch. 7 - Review Question 7.4 If the magnitude of the force...Ch. 7 - Review Question 7.5 Why, when friction cannot be...Ch. 7 - Review Question 7.6 What would change in the...Ch. 7 - Review Question 7.7 Imagine that a collision...Ch. 7 - Review Question 7.8 Toyota says that the power of...Ch. 7 - Review Question 7.9 In this section you read that...Ch. 7 - In which of the following is positive work done by...
Ch. 7 - 2. Which answer best represents the system’s...Ch. 7 - An Atwood machine is shown in Figure Q7.3. As the...Ch. 7 - Prob. 4MCQCh. 7 - 5. Three processes are described below. Choose one...Ch. 7 - 6. Choose which statement describes a process in...Ch. 7 - 7. Which example(s) below involve(s) zero physics...Ch. 7 - 8. Estimate the change in gravitational potential...Ch. 7 - What does it mean if object 1 does +10 J of work...Ch. 7 - You pull on a spring, which obeys Hookes law, in...Ch. 7 - The graph in Figure Q7.11 shows the time...Ch. 7 - 12. A 1400-kg car is traveling on a level road at...Ch. 7 - Prob. 13MCQCh. 7 - Two clay balls are moving toward each other. The...Ch. 7 - 15. Is energy a physical phenomenon, a model, or a...Ch. 7 - 16. Your friend thinks that the escape speed...Ch. 7 - Suggest how you can measure the following...Ch. 7 - How can satellites stay in orbit without any jet...Ch. 7 - Why does the Moon have no atmosphere, but Earth...Ch. 7 - What will happen to Earth if our Sun becomes a...Ch. 7 - 21. In the equation , the gravitational potential...Ch. 7 - 22. You push a small cart by exerting a constant...Ch. 7 - 1. Jay fills a wagon with sand (about 20 kg) and...Ch. 7 - 2. You have a 15-kg suitcase and (a) slowly lift...Ch. 7 - * You use a rope to slowly pull a sled and its...Ch. 7 - A rope attached to a truck pulls a 180-kg...Ch. 7 - 5. You lift a 25-kg child 0.80 m, slowly carry him...Ch. 7 - A truck runs into a pile of sand, moving 0.80 m as...Ch. 7 - 7. A 0.50-kg block is placed in a straight gutter...Ch. 7 - s up a smooth incline, which makes an angle with...Ch. 7 - 9. ** It is a windy day. You are moving a 20-kg...Ch. 7 - A 5.0-kg rabbit and a 12-kg Irish setter have the...Ch. 7 - Prob. 11PCh. 7 - * A pickup truck (2268 kg) and a compact car (1100...Ch. 7 - * When does the kinetic energy of a car change...Ch. 7 - * When exiting the highway, a 1100-kg car is...Ch. 7 - Prob. 15PCh. 7 - 16. * Flea jump flea pushes off a surface by...Ch. 7 - * Roller coaster ride A roller coaster car drops a...Ch. 7 - 18. * BIO EST Heart pumps blood The heart does...Ch. 7 - 19. * Wind energy Air circulates across Earth in...Ch. 7 - 20. * BIO Bone break The tibia bone in the lower...Ch. 7 - 21. * BIO EST Climbing Mt. Everest In 1953 Sir...Ch. 7 - 22. A door spring is difficult to stretch. (a)...Ch. 7 - * A moving car has 40,000 J of kinetic energy...Ch. 7 - 24. * The force required to stretch a slingshot by...Ch. 7 - Jim is driving a 2268-kg pickup truck at 20 m/s...Ch. 7 - 26. * A car skids 18 m on a level road while...Ch. 7 - s mass is m. An average friction force of...Ch. 7 - Prob. 28PCh. 7 - Prob. 29PCh. 7 - 30. In a popular new hockey game, the players use...Ch. 7 - 31. The top of a descending ski slope is 50 m...Ch. 7 - * If 20% of the gravitational potential energy...Ch. 7 - Prob. 33PCh. 7 - 34. A driver loses control of a car, drives off an...Ch. 7 - * You are pulling a box so it moves at increasing...Ch. 7 - s speed increases from zero to 4.0 m/s in a...Ch. 7 - 37. ** EST Hit by a hailstone A 0.030-kg hailstone...Ch. 7 - 38. * BIO Froghopper jump Froghoppers may be the...Ch. 7 - 39. * Bar chart Jeopardy 1 Describe in words and...Ch. 7 - * Bar chart Jeopardy 2 Describe in words and with...Ch. 7 - 41. * Equation Jeopardy 1 Construct a qualitative...Ch. 7 - * Equation Jeopardy 2 Construct a qualitative...Ch. 7 - Prob. 43PCh. 7 - 44. * Evaluation 2 Your friend provides a solution...Ch. 7 - 45. A crab climbs up a vertical rock with a...Ch. 7 - 46 * Work-energy bar charts for a person going...Ch. 7 - Prob. 47PCh. 7 - * A 1060-kg car moving west at 16 m/s collides...Ch. 7 - * You fire an 80-g arrow so that it is moving at...Ch. 7 - 50. * You fire a 50-g arrow that moves at an...Ch. 7 - * To confirm the results of Problem 7.50, you try...Ch. 7 - 52. * Somebody tells you that Figure P7.52 shows...Ch. 7 - 54. A roofing shingle elevator is lifting a...Ch. 7 - 55. (a) What is the power involved in lifting a...Ch. 7 - * A fire engine must lift 30 kg of water a...Ch. 7 - * BIO Internal energy change while biking You set...Ch. 7 - * Climbing Mt. Mitchell An 82-kg hiker climbs to...Ch. 7 - * BIO EST Sears stair climb The fastest time for...Ch. 7 - * BIO EST Exercising so you can eat ice cream You...Ch. 7 - 61. ** BIO Salmon move upstream In the past,...Ch. 7 - * EST Estimate the maximum horsepower of the...Ch. 7 - Prob. 63PCh. 7 - At what distance from Earth is the gravitational...Ch. 7 -
65. * Possible escape of different air molecule...Ch. 7 - Determine the escape speed for a rocket to leave...Ch. 7 - Determine the escape speed for an object to leave...Ch. 7 - If the Sun were to become a black hole, how much...Ch. 7 - * A satellite moves in elliptical orbit around...Ch. 7 - 70. * Determine the maximum radius Earth's Moon...Ch. 7 - 71. You throw a clay ball vertically upward. The...Ch. 7 - Prob. 72GPCh. 7 - Prob. 73GPCh. 7 - 74 * EST A “gravity force car” is powered by the...Ch. 7 - * Loop the loop You are given a loop raceway for...Ch. 7 - 76. ** Atwood machine Two blocks of masses hang...Ch. 7 - andm2 are connected with a string that passes over...Ch. 7 - of all species became extinct, ending the reign of...Ch. 7 - s cradle is a toy that consists of several metal...Ch. 7 - 81. ** Six Flags roller coaster A loop-the-loop on...Ch. 7 - ** Designing a ride You are asked to help design a...Ch. 7 - BIO Metabolic rate Energy for our activities is...Ch. 7 - BIO Metabolic rate Energy for our activities is...Ch. 7 - BIO Metabolic rate Energy for our activities is...Ch. 7 - BIO Metabolic rate Energy for our activities is...Ch. 7 - BIO Metabolic rate Energy for our activities is...Ch. 7 -
BIO Kangaroo hopping Hopping is an efficient...Ch. 7 - BIO Kangaroo hopping Hopping is an efficient...Ch. 7 - BIO Kangaroo hopping Hopping is an efficient...Ch. 7 - BIO Kangaroo hopping Hopping is an efficient...Ch. 7 - BIO Kangaroo hopping Hopping is an efficient...Ch. 7 - BIO Kangaroo hopping Hopping is an efficient...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Write each number in scientific notation.
5. 826.4
Applied Physics (11th Edition)
What is the volume of one mole of air, at room temperature and 1 atm pressure?
An Introduction to Thermal Physics
TEST YOUR UNDERSTANDING OF SECTION 1.8 Two vectors and lie in the xy-plane. (a) Can have the same magnitude ...
University Physics with Modern Physics (14th Edition)
Express the unit vectors in terms of (that is, derive Eq. 1.64). Check your answers several ways Also work o...
Introduction to Electrodynamics
In the figure below weve replaced one of the hands from Fig. 5.9 with a hook attaching the rope to a wall. On t...
Essential University Physics (3rd Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- A particle is subject to a force Fx that varies with position as shown in Figure P7.9. Find the work done by the force on the particle as it moves (a) from x = 0 to x = 5.00 m, (b) from x = 5.00 m to x = 10.0 m, and (c) from x = 10.0 m to x = 15.0 m. (d) What is the total work done by the force over the distance x = 0 to x = 15.0 m?arrow_forwardA boy starts at rest and slides down a frictionless slide as in Figure P5.64. The bottom of the track is a height h above the ground. The boy then leaves the track horizontally, striking the ground a distance d as shown. Using energy methods, determine the initial height H of the boy in terms of h and d. Figure P5.64arrow_forwardGive an example of a situation in which there is a force and a displacement, but the force does no work. Explain why it does no work.arrow_forward
- Suppose the ski patrol lowers a rescue sled and victim, having a total mass of 90.0 kg, down a 60.0° slope at constant speed, as shown in Figure 7.37. The coefficient of friction between the sled and the snow is 0.100. (a) How much work is done by friction as the sled moves 30.0 m along the hill? (b) How much work is done by the rope on the sled in this distance? (c) What is the work done by the gravitational force on the sled? (d) What is the total work done?arrow_forwardA block is placed on top of a vertical spring, and the spring compresses. Figure P8.24 depicts a moment in time when the spring is compressed by an amount h. a. To calculate the change in the gravitational and elastic potential energies, what must be included in the system? b. Find an expression for the change in the systems potential energy in terms of the parameters shown in Figure P8.24. c. If m = 0.865 kg and k = 125 N/m, find the change in the systems potential energy when the blocks displacement is h = 0.0650 m, relative to its initial position. FIGURE P8.24arrow_forwardA nonconstant force is exerted on a particle as it moves in the positive direction along the x axis. Figure P9.26 shows a graph of this force Fx versus the particles position x. Find the work done by this force on the particle as the particle moves as follows. a. From xi = 0 to xf = 10.0 m b. From xi = 10.0 to xf = 20.0 m c. From xi = 0 to xf = 20.0 m FIGURE P9.26 Problems 26 and 27.arrow_forward
- A block of mass m = 2.50 kg is pushed a distance d = 2.20 m along a frictionless, horizontal table by a constant applied force of magnitude F = 16.0 N directed at an angle = 25.0 below the horizontal as shown in Figure P6.3. Determine the work done on the block by (a) the applied force, (b) the normal force exerted by the table, (c) the gravitational force, and (d) the net force on the block. Figure P6.3arrow_forwardA particle moves in one dimension under the action of a conservative force. The potential energy of the system is given by the graph in Figure P8.55. Suppose the particle is given a total energy E, which is shown as a horizontal line on the graph. a. Sketch bar charts of the kinetic and potential energies at points x = 0, x = x1, and x = x2. b. At which location is the particle moving the fastest? c. What can be said about the speed of the particle at x = x3? FIGURE P8.55arrow_forwardThe force acting on a panicle varies as shown in Figure la P7.14. Find the work done by the force on the particle as it moves (a) from x = 0 to x = 8.00 m. (b) from x = 8.00 m to x = 10.0 m, and (c) from x = 0 to x = 10.0 m.arrow_forward
- As a simple pendulum swings back and forth, the forces acting on the suspended object are the force of gravity, the tension in the supporting cord, and air resistance, (a) Which of these forces, if any, does no work on the pendulum? (b) Which of these forces does negative work at all times during the pendulums motion? (c) Describe the work done by the force of gravity while the pendulum is swinging.arrow_forwardA particle moves in the xy plane (Fig. P9.30) from the origin to a point having coordinates x = 7.00 m and y = 4.00 m under the influence of a force given by F=3y2+x. a. What is the work done on the particle by the force F if it moves along path 1 (shown in red)? b. What is the work done on the particle by the force F if it moves along path 2 (shown in blue)? c. What is the work done on the particle by the force F if it moves along path 3 (shown in green)? d. Is the force F conservative or nonconservative? Explain. FIGURE P9.30 In each case, the work is found using the integral of Fdr along the path (Equation 9.21). W=rtrfFdr=rtrf(Fxdx+Fydy+Fzdz) (a) The work done along path 1, we first need to integrate along dr=dxi from (0,0) to (7,0) and then along dr=dyj from (7,0) to (7,4): W1=x=0;y=0x=7;y=0(3y2i+xj)(dxi)+x=7;y=0x=7;y=4(3y2i+xj)(dyj) Performing the dot products, we get W1=x=0;y=0x=7;y=03y2dx+x=7;y=0x=7;y=4xdy Along the first part of this path, y = 0 therefore the first integral equals zero. For the second integral, x is constant and can be pulled out of the integral, and we can evaluate dy. W1=0+x=7;y=0x=7;y=4xdy=xy|x=7;y=0x=7;y=4=28J (b) The work done along path 2 is along dr=dyj from (0,0) to (0,4) and then along dr=dxi from (0,4) to (7,4): W2=x=0;y=0x=0;y=4(3y2i+xj)(dyj)+x=0;y=4x=7;y=4(3y2i+xj)(dyi) Performing the dot product, we get: W2=x=0;y=0x=0;y=4xdy+x=0;y=4x=7;y=43y2dx Along the first part of this path, x = 0. Therefore, the first integral equals zero. For the second integral, y is constant and can be pulled out of the integral, and we can evaluate dx. W2=0+3y2x|x=0;y=4x=7;y=4=336J (c) To find the work along the third path, we first write the expression for the work integral. W=rtrfFdr=rtrf(Fxdx+Fydy+Fzdz)W=rtrf(3y2dx+xdy)(1) At first glance, this appears quite simple, but we cant integrate xdy=xy like we might have above because the value of x changes as we vary y (i.e., x is a function of y.) [In parts (a) and (b), on a straight horizontal or vertical line, only x or y changes]. One approach is to parameterize both x and y as a function of another variable, say t, and write each integral in terms of only x or y. Constraining dr to be along the desired line, we can relate dx and dy: tan=dydxdy=tandxanddx=dytan(2) Now, use equation (2) in (1) to express each integral in terms of only one variable. W=x=0;y=0x=7;y=43y2dx+x=0;y=0x=7;y=4xdyW=y=0y=43y2dytan+x=0x=7xtandx We can determine the tangent of the angle, which is constant (the angle is the angle of the line with respect to the horizontal). tan=4.007.00=0.570 Insert the value of the tangent and solve the integrals. W=30.570y33|y=0y=4+0.570x22|x=0x=7W=112+14=126J (d) Since the work done is not path-independent, this is non-conservative force. Figure P9.30ANSarrow_forwardA student expends 7.5 W of power in lifting a textbook 0.50 m in 1.0 s with a constant velocity. (a) How much work is done, and (b) how much does the book weigh (in newtons)? The answers to Confidence Exercises may be found at the back of the book.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
University Physics Volume 1
Physics
ISBN:9781938168277
Author:William Moebs, Samuel J. Ling, Jeff Sanny
Publisher:OpenStax - Rice University
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Mechanical work done (GCSE Physics); Author: Dr de Bruin's Classroom;https://www.youtube.com/watch?v=OapgRhYDMvw;License: Standard YouTube License, CC-BY