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# Work and Power Practice Problems pdf

Problems: Work, Energy, Power 1) A 10.0 kg mass sliding on a frictionless horizontal surface at 7.00 m/s hits a spring that is attached to a wall. The spring has a spring constant of 5000 N/m. a) Determine the maximum compression of the spring. At maximum compression, the box has a speed of zero. Therefore, comparing just before it hits the. View Work and Power Practice Problems.pdf from PHYSICS (1202/2110 at University of North Carolina, Charlotte. Work and Power Practice Problems Name _ Date _ To believe all men honest would be folly AP Physics 1- Work, Energy, & Power Practice Problems ANSWERS FACT: The amount of work done by a steady force is the amount of force multiplied by the distance an object moves parallel to that force: W = F x cos (θ). The units are N. m, which equal a Joule (J). Positive work is done by a force parallel to an object's displacement

### Work and Power Practice Problems

Work, Power and Energy Practice Problems Work and Power Problems 1) How much work will you do if you push a block of concrete 4.3 m along a floor with a steady force of 25 N? 2) If your mass is 70.0 kg, how much work will you do climbing a flight of stairs 25.0 mhigh, moving at a steady pace? 3) Your car is stuck in the mud Work and Power Worksheet Answer each question by calculating for the missing variable. Be sure to show all calculation work in the space provided. Please circle your final answer and be sure it has the proper label. 1. You must exert a force of 4.5 N on a book to slide it across a table. If you do 2.7 Physics Practice Problems: Work and Energy Page 2 of 5 Power: 20. A skier of mass 70 kg is pulled up a slope by a motor-driven cable. a) How much power is required to pull him 100 m up a 30º frictionless slope at a constant speed of 2 m/s? b) How many horsepower (hp) output must a motor have to perform this task?. the more work you perform. • There are only two relevant variables in one dimension: the force, F x, and the displacement, Δx. Work W is the energy transferred to or from an object by means of a force acting on the object. Energy transferred to the object is positive work, and energy transferred from the object is negative work Work Practice Problems Worksheet #1 ANSWER KEY. Amy uses 20N of force to push a lawn mower 10 meters. How much work does she do? Work = Force X Distance. Work = 20N X 10m. Work = 200 J. 2) How much work does an elephant do while moving a circus wagon 20 meters with a pulling force of 200N? Work = Force X Distance. Work = 200N X 20m. Work = 4000 5-1 Work and Power 63 5-2 Energy 66 5-3 Machines and Efficiency 72 often referred to as problem solving.Problem solving, however, is more than A section of Practice Exercises allows you to apply some of the skills you have learned to new situations. For more practice, at the end of each chapter there is a section of Additional. Ohm's Law and Power Equation Practice Worksheet Name_____ Period_____ Date_____ Show all four steps for each problem STEP1 - RECORD INFO STEP 2 - WRITE EQUATION STEP 3 - SUBSTITUTE IN THE EQUATION STEP 4 - SOLVE 1. Find the current through a 12-ohm resistive circuit when 24 volts is applied. 2. Find the resistance of a circuit that draws 0.06. Power of Power 3. Interactive Notes: Includes a review of exponents and covers the 3 rules. Practice is provided on the notes 4. A Practice worksheet which covers Rule #1 and #2 only. You will probably not cover all the rules on the first day. (This is two half sheets on one page) 5. A homework assignment which covers Rule #1 and #2 only

### Work Energy Power Problems with Solutions

• Work Practice Problems Show all work! No naked numbers! 1) Amy uses 20N of force to push a lawn mower 10 meters. How much work does she do? 2) How much work does an elephant do while moving a circus wagon 20 meters with a pulling force of 200N? 3) Alex applies 350 N of force to move his stalled car 40 m, how much work did Alex do
• Download Work Energy Power Problems with Solutions.pdf (497 KB) Equella is a shared content repository that organizations can use to easily track and reuse content. This OER repository is a collection of free resources provided by Equella
• Microsoft Word - Worksheet - Work and Power ProblemsKey Author: Indira Created Date: 3/21/2016 6:37:49 PM.
• Physics 1120: Work & Energy Solutions Energy 1. In the diagram below, the spring has a force constant of 5000 N/m, the block has a mass of 6.20 kg, and the height h of the hill is 5.25 m. The problem involves a change in height and speed and has a spring, so we apply the generalized Work­ Energy.

### Work, Energy, & Power Practice Problems (2)

We define power as ! Power = work done time taken and using symbols, we write this as ! P= F x d ( ) t Power is measured in Watts. Example: A person of mass 70kg runs up a flight of stairs with a vertical height of 5m. If the trip takes 7s to complete, calculate the person's power. Solution: WD = E p = mgh = 70 x 10 x 5 = 3500J ! Power = work. EXPONENT RULES & PRACTICE 1. PRODUCT RULE: To multiply when two bases are the same, write the base and ADD the exponents. Examples: A. B. C. 2. QUOTIENT RULE: To divide when two bases are the same, write the base and SUBTRACT the exponents. Examples: A. B. ˘ C. ˇ ˇ 3 In Physics, power is associated with energy and has a precise meaning. The concept of power is concerned with how rapidly energy is being transferred or transformed when work is done. It is the rate of work done or rate of energy transfer. Power is measured in joules per second (J/s) r o watts (W) and is worked out using the formula Work & Energy Multiple Choice Problems. Slide 2 / 76 1 A driver in a 2000 kg Porsche wishes to pass a slow moving school bus on a 4 lane road. What is the average power in watts required to accelerate the sports car from 30 m/s to 60 m/s in 9 seconds? A 1,800 B 5,000 C 10,000 D 100,000 E 300,000. Slide 3 / 7 AP Physics Practice Test: Work, Energy, Conservation of Energy ©2011, Richard White www.crashwhite.com Part II. Free Response 6. A block of mass m rests on a rough surface, and has a light spring of spring constant k and unstretched length d attached to one side as shown, with the other end of the spring attached to an anchor. There is

Work, Energy, & Power Practice Problems Example 1: A 25 kg crate is pulled 5 m across a horizontal floor using an applied force of 250 N directed 30 o above the horizontal. The coefficient of sliding (kinetic) friction between the bottom of the crate and the floor is 0.15. Determine the work done on the crate by: (a) The applied force. (b) The frictional force Work Energy and Power Practice Question Bank PDF. This PDF file is a compilation of various previous year questions from work energy and power. This PDF file is very important for the JEE Mains Aspirants. Users can download the question bank pdf along with solutions from the link given below. Click - To Download Question Bank PDF free Keys for extra practice below! Work and Power. File Size: 211 kb. File Type: pdf. Download File. Kinetic and Potential. File Size 1.1 Work is the product of the displacement of the object and the component of the force parallel to the plane or the movement of the object. 1.2 Energy is the ability of to do work. 1.3 Power is the rate at which work is done. 1.4 The conservative force is the force which does no net work on an object which is on a closed path. Question Electrical Power 14.3 How do you calculate electrical power? In this skill sheet you will review the relationship between el ectrical power and Ohm's law. As you work through the problems, you will practice calculating the power used by common appliances in your home

energy problem with solution in example work power energy pdf solution dynamics kinematics fundamentals of optics exam solutions energy momentum vibration problems solving work, energy and power problems and solutions pdf solve problem dynamics electricity physics/ electric current impulse wave Dynamics Exam and Problem Solution Problem 8: The Taipei 101 in Taiwan is a 1667-foot tall, 101-story skyscraper. The skyscraper is the home of the world's fastest elevator. The elevators transport visitors from the ground floor to the Observation Deck on the 89th floor at speeds up to 16.8 m/s. Determine the power delivered by the motor to lift the 10 passengers at this speed Work Power Energy Exams1 (Work) and Problem Solutions 1. In the picture given above F pulls a box having 4kg mass from point A to B. If the friction constant between surface and box is 0,3; find the work done by F, work done by friction force and work done by resultant force. Work done by F; WF=F. X=20. 5=100 joule Work done by friction force; Wfriction=-Ff Work and Power Practice Problems . Name_____ Amy uses 20N of force to push a lawn mower 10 meters. How much work does she do? Joe balances a stationary coin on the tip of his finger 20cm from the top of the table. How much work is Joe doing? Frank does 2400J of work in climbing a set of stairs.. Work, Energy, and Power Practice Problems Name: 1. Renatta Gass is out with her friends. Misfortune occurs and Renatta and her friends find themselves getting a workout. They apply a cumulative force of 1080 N to push the car 218 m to the nearest fuel station. Determine the work done on the car. 2. Hans Full is pulling on a rope to drag hi

Worksheet - Work & Power Problems EXTRA PRACTICE! I. Work A. Sample Problems: 1. F = 200 Newtons d = 50 meters W = ? 2. F = 5 Newtons W = 75 Joules D = ? 3. W = 125 Joules d = 10 meters F = ? 4. If 150 Joules of work is needed to move a box 10 meters, what force was used? 5. In question #4, what was the mass of the box Work, Energy, & Power Practice Quiz Name_____ VOCABULARY: IDENTIFY THE FOLLOWING 1. The SI units for energy and work JOULES 2. SI unit for power that is equivalent to Joules/second. WATTS 3. Type of energy associated with the motion of an object. KINETIC 4

Work & Energy Word Problems Calculating Work Work has a special meaning in science. It is the product of the force applied to an object and the distance the object moves. The unit of work is the Joule (J) Work = Force x Distance W= F x d Work = joules (J) Force = newtons (N) Distance = meters (m) 1. A book weighing 1.0 newton is lifted 2 meters a. more work in a longer time interval. b. the same work in a shorter time interval. c. less work in a longer time interval. d. the same work in a longer time interval. 31. What happens to power produced if more work is done in the same amount of time? a. Power increases b. Power decreases c. Power remains constant d. Not enough information 32 The box moves 4.0 m to the right. Find the work done by (a) the girl, (b) the boy, and (c) the net force. 5. If 100 N force has 30o angle pulling on 15 kg block for 5 m. What's the work? 6. Calculate the power expended when a 500 N barbell is lifted 2.2 m in 2 s. 7. An escalator is used to move 20 passengers every minut Question TitleWork Problems V continued Compare the work done by and external power exerted by the jogger in the intervals A to B and C to D. *The power is external because we are ignoring contributions form internal work such as maintaining body temperature* *Acceleration due to gravity is 9.82 m/s2* A. Power AB > Power CD and Work AB = Work. work and power. If you understand work, you can make your work easier. Review Vocabulary force: a push or a pull New Vocabulary• •work power Figure 1 This girl is holding bags of groceries, yet she isn't doing any work. Explain what must happen for work to be done. Work and Power Mary Kate Denny/PhotoEdit, Inc. 639-S1-MSS05 8/13/04 4:47.

### Work Energy and Power Question Bank PDF Downloa

• Power is the rate at which is done. Power is measured in . Rule for Power Power = Work / Time (in Watts) (in Joules) (in seconds) P = W / T Questions 1. Why are both energy and work measured in Joules? 2. A ball with a weight of 30 Newtons is kicked 2 metres into the air. What work has been done? 3
• Work, Power, and Energy Solved question PDF. Work, Power, and Energy Questions PDF download. IIT-JEE Work, Power and Energy solved questions PDF. Hi friends today we are providing 200 Important questions on work power and energy.These are the most important questions for J EE Main, Advance, UPSEE, BITSAT and all other entrance exams
• 4a-Work-Energy MC practice problems.doc. Work & Energy MC Key. 4c-Work-Energy MC practice problems-ANSWERS.doc. Work & Energy FR. 4b-Work-Energy FR practice problems.doc. Work & Energy FR Key. 4d-Work-Energy FR practice problems-ANSWERS.doc. Momentum & Impulse MC. 5a-Momentum and Impulse MC practice problems.doc. Momentum & Impulse MC Ke

### Unit 4 Work, Power, and Energy - Physical Scienc

1. ation, an artist painting a beautiful landscape, all are said to be working. In physics, however
2. 3-7: Electric Power Kilowatt Hours The kilowatt hour (kWh) is a unit commonly used for large amounts of electrical work or energy. For example, electric bills are calculated in kilowatt hours. The kilowatt hour is the billing unit. The amount of work (energy) can be found by multiplying power (in kilowatts) × time in hours
3. ator and then solving the resulting equation
5. Since work is the change in kinetic energy, calculate the work done by each force.The work can be positive, nega-tive, or zero, depending on the relative angles of the force and displacement of the object.The sum of the three works is the change in energy of the system. Practice Problems 10.2 Machines pages 266-273 page 272 24
6. L.C.M method to solve time and work problems. Translating the word problems in to algebraic expressions. Remainder when 2 power 256 is divided by 17. Remainder when 17 power 23 is divided by 16. Sum of all three digit numbers divisible by 6. Sum of all three digit numbers divisible by 7. Sum of all three digit numbers divisible by

### Exams and Problem Solutions - Physics Tutorial

1. Numerical Problems, Conceptual Questions, Solved Example Problems : Physics : Work, Energy and Power : Solved Example Problems for Physics: Work, Energy and Power. Numerical Problems. 1. Calculate the work done by a force of 30 N in lifting a load of 2kg to a height of 10m (g = 10ms-2
2. Work = Force x distance. Power = Work / Time = Force x distance / time. SHOW YOUR WORK AND REMEMBER YOUR UNITS. How much work is done when an 8 N force moves a block 7m? [2 Points] Eva applies 40N force to move her bookcase 3m, how much work did Eva do? [2 Pts] How far will 490 J of work raise a block weighing 7 N? [3 Points
3. In order to have a hold on any subject, it is only possible with regular studies and practice. Work, Energy, and Power is a chapter that can be understood with real-life exams. Work energy and power Class 11 important questions with answers covered all the questions with suitable examples students can relate it to quickly
4. W = 0,300 x 10 x 0,80. W = 2,4 joule. Problem 8. A boy of 450 N of weight climbs a wood steps with a lenght of 3 m. The boy takes 6 seconds to get the end of the steps. What is the power done by the boy on this activity! Answer. The power (P), the work (W) and the time (t) relationship: P = W/t
5. February 11, 2019. Some of the worksheets below are Work, Power and Energy Free Worksheets, definitions of Energy, work-energy principle, different forms of energy, the principle of conservation of energy, work-kinetic energy theorem, student notes, . Once you find your worksheet (s), you can either click on the pop-out icon or.

### Mechanics: Work, Energy and Power - Physics Classroo

1. SOCIAL WORK The appropriation of power or 'empowerment' must be a major concern for social workers in all aspects of the practice of social work — whether individual, group or community. Though the term 'empowerment' is relatively recent and very catchy, its roots go back to the very begin­ nings of social work
2. Guided notes to accompany introduction PowerPoint (my primary free product!) and practice problems including solving for work and power, identifying when work is done, and a fill-in-the blank review section of vocab from work, power, force, etc.Designed to accompany: PowerPoint Introduction to work
3. Power Problems in Physics. When it comes to work in physics, you're sure to see problems involving power, which is the amount of work being done in a certain amount of time. Here's the equation for power, P: W equals force along the direction of travel times distance, so you could write the equation for power this way: where theta is the.
4. Free PDF Download of JEE Main Work, Energy and Power Important Questions of key topics. Practice JEE Main Important Topics Questions solved by our expert teachers helps to score good marks in IIT JEE Exams
5. BrainpopAccelerationActivity.pdf View Download: Section 1: Brainpop Acceleration 1 Work and Power PRACTICE PROBLEMS.

Work And Power Problems. Work And Power Problems - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are 6 1213 work wkst, A guide to work energy and power, Work and power work 1, Work word problems, Work 51 math in science physical work and power, Problems work energy power 1 a kg mass sliding on, Work energy and power, 501 math word problems Sat Physics subject questions on energy, work and power, with detailed solutions, similar to the questions in the SAT test are presented. Answers at the bottom of the page and also detailed solutions and explanations. How much work is done in pulling a box, on the ground, for 20 meters with a force of 20 Newtons making an angle of 10° with the ground 7. A 0.1-kg thrown horizontally at 6 m/s from the height of 5 meters. If the acceleration of gravity is 10 m/s 2, then what is the kinetic energy of ball at the height of 2 meters.. Known : Mass (m) = 0.1 kg. The change in height (h) = 5 m - 2 m = 3 meter Work, Power and Energy is an important chapter in JEE. Solving previous years' question papers helps the students to analyse the pattern of questions and to understand the method of studies. Download Work Power and Energy Previous Year Solved Questions PDF JEE Main Previous Year Solved Questions on Work, Power and Energ

Work is represented by the product of force and displacement: We are given the force on the box and the distance it travels. Use these values to calculate the work done. Note that the mass of the box for this problem is irrelevant. There is no vertical displacement, so the force of gravity does not come into play Power (P) is the word used to describe the rate at which work is done (or energy is transformed).Power may be confused by thinking that a more powerful machine does more work.This is not true. For example, if you have to people, one who does work in 5 seconds, and the other in 8 seconds but both do the same amount of work, which will more powerful?The answer is the one who does the same amount. Read and download free pdf of CBSE Class 9 Science Work And Energy Worksheet Set A. Students and teachers of Class 9 Science can get free printable Worksheets for Class 9 Science in PDF format prepared as per the latest syllabus and examination pattern in your schools. Standard 9 students should practice questions and answers given here for Science in Grade 9 which will help them to improve.

### Work Power Energy Exam1 and Problem Solution

Free Math Worksheets. Math-Drills.com includes over 58 thousand free math worksheets that may be used to help students learn math. Our math worksheets are available on a broad range of topics including number sense, arithmetic, pre-algebra, geometry, measurement, money concepts and much more. There are two interactive math features: the math. Explanation: . Since this question refers to work done by nonconservative forces, we know that: Here, is the change in potential energy, and is a change in kinetic energy. is because the object returns to the same height as when it was launched. however has changed because the object's velocity has changed. Recall that the formula for the change in kinetic energy is given by

### Work and Power Practice Problem

5.3 Work-energy theorem (ESCMD) Conservative and non-conservative forces (ESCMF). In Grade 10, you saw that mechanical energy was conserved in the absence of non-conservative forces. It is important to know whether a force is an conservative force or an non-conservative force in the system, because this is related to whether the force can change an object's total mechanical energy when it does. Power Practice Problems for the Electrical and Computer PE Exam provides you with the problem-solving practice and confidence you need to succeed on your exam. To provide well-rounded, streamlined exam preparation, this book features 535 problems in varying formats and levels of difficulty and coordinates with the chapters in the Power.

### Unit 9 (Work, Energy, Power, and Simple Machines) Practice

Work can also be represented on a graph by plotting the magnitude of the force (F), on the y-axis and the magnitude of the object's position (d) on the x-axis. The F-d graph on the left shows the constant force acting through a displacement (the red part).Positive and negative work (when the force and displacement are in opposite directions) can also be displayed on F-d graphs Math 122B - First Semester Calculus and 125 - Calculus I. Worksheets. The following is a list of worksheets and other materials related to Math 122B and 125 at the UA. Your instructor might use some of these in class. You may also use any of these materials for practice. The chapter headings refer to Calculus, Sixth Edition by Hughes-Hallett et. ADDITIONAL PRACTICE 1. The most powerful ice breaker in the world was built in the former So-viet Union. The ship is almost 150 m long, and its nuclear engine gener-ates 56 MW of power. How much work can this engine do in 1.0 h? 2. Reginald Esuke from Cameroon ran over 3 km down a mountain slope in just 62.25 min. How much work was done if the.

Work, Power and Energy Worksheet. Conceptual Physics: Work and Power. 1. Calculate the work done by a 47 N force pushing a pencil 0.26 m. 2. Calculate the work done by a 47 N force pushing a 0.025 kg pencil 0.25 m against a force of 23 N. 3. Calculate the work done by a 2.4 N force pushing a 400. g sandwich across a table 0.75 m wide. 4 AP Physics 1- Work and Energy Practice Problems (2019) FACT: The amount of work done by a steady force is the amount of force multiplied by the distance an object moves parallel to that force: W = F x cos (θ). The units are N · m, which equal a Joule (J). Positive work is done by a force parallel to an object's displacement The SI unit for work is the newton-meter (N m), also known as a joule (J).You can calculate the amount of work accomplished with the equation above. Let's see how it's done! SAMPLE PROBLEM: How much work is done on a 16 N sack of potatoes when you lift the sack 1.5 m? W 16N 1.5m W 24J Work It Out! Based on what you know about work, answer. Energy Practice Problems PSI AP Physics B Name_____ 1. A driver in a 2000 kg Porsche wishes to pass a slow moving school bus on a 4 lane road. What is the average power in watts required to accelerate the sports car from 30 m/s to 60 m/ If a problem asks you to calculate the voltage or resistance, you must rearrange the equation 1=V/R to solve for J or R. All three forms of the equation are listed below. v = IR PRACTICE In this section, you will find some problems based on diagrams and others without diagrams. In all cases, your work. l

### Work,Power and Energy Important question PDF for JEE Main

1. Work, Power, Energy Worksheet . 1. Calculate the work done by a 47 N force pushing a pencil 0.26 m. 2. Calculate the work done by a 47 N force pushing a 0.025 kg pencil 0.25 m against a force of 23 N. 3. Calculate the work done by a 2.4 N force pushing a 400 g sandwich across a table 0.75 m wide
2. ary work 2 How to use this booklet 2 Re
3. e.
4. world.The materials are organized by chapter and lesson, with one Word Problem Practice worksheet for every lesson in Glencoe Math Connects, Course 1. Always keep your workbook handy. Along with your textbook, daily homework, and class notes, the completed Word Problem Practice Workbookcan help you in reviewing for quizzes and tests

### PHYSICS All Worksheets with Key

Created Date: 12/6/2012 3:51:59 P Archimedes' Principle, Pascal's Law and Bernoulli's Principle Lesson— Practice Problems Worksheet Answer Key 2 3. Water circulates throughout a house in a hot water heating system. If the water is pumped at a speed of 0.50 m/s through a 4.0-cm diameter pipe in the basement under a pressure of 3.03x10 Incorrect: Wind is an enduring source of power. Water is also an unlimited energy source. Dams produce hydraulic power. They have existed for a long time. Windmills are relatively new. Correct: Both wind and water are enduring sources of power. Dams have produced hydraulic power for a long time, but windmills are relatively new

Practice Integration Math 120 Calculus I D Joyce, Fall 2013 This rst set of inde nite integrals, that is, an-tiderivatives, only depends on a few principles of integration, the rst being that integration is in-verse to di erentiation. Besides that, a few rules can be identi ed: a constant rule, a power rule Power • The average power Class Problem 1 (con't) a) Calculate the work done by the pushing force. b) Calculate the work done by the friction force. c) What is the average power of the Practice this, so you get 1 or 2 peaks of the force in 10 s, then record the force with DataStudio power of man. To try to work with them in a disciplined way is like trying to har-ness the power of the elements and includes the same kind of scientific thinking, as well as serious consideration of ethics. Like atomic power, groups can be harmful and helpful. To work with such power is a humbling and difficult task. (Konopka, 1963: vii-viii

Practice: Work and energy questions. This is the currently selected item. Work example problems. Conservation of energy. Work/energy problem with friction. Intro to springs and Hooke's law. Potential energy stored in a spring. Spring potential energy example (mistake in math) Work as the transfer of energy. Work can be negative. MCQ on Work Power Energy (pdf) for competitive exams specially for Railway technician, loco pilot, NDA, CDS and IAS. This is a physics quiz practice set 1 provided by gkarea.com. All important questions are listed with answer. Download MCQ on Work Power Energy PDF. Save As PDF ### Video: Solving Problems Involving Wor    Here, I will present solve problems typical of those offered in a mathematical economics or advanced microeconomics course. The problems were originally compiled by Dr. Charles N. Steele and are reprinted with his generous permission. The solutions to the problems are my own work and not necessarily the only way to solve the problems part of social work since its inception, and some writers have argued that it represents a critical component of effective social work (Teater 2010). Although the relational aspect of social work has been foundational in social work thinking and practice, it has nevertheless not been without criticism Exponents Worksheet For 8th Grade, Exponents Worksheet For Grade 8, Exponents Worksheet For 6th Grade, Exponents Worksheet Fun, Exponents Worksheet For Class 7, Exponents Worksheet For Class 8, Exponents Worksheet Fifth Grade, Worksheet For Exponents And Square Roots, Exponent Worksheet Find The Value Of Each Expression, Worksheets Exponents. Here is a set of practice problems to accompany the Power Series section of the Series & Sequences chapter of the notes for Paul Dawkins Calculus II course at Lamar University Math 129 - Calculus II. Worksheets. The following is a list of worksheets and other materials related to Math 129 at the UA. Your instructor might use some of these in class. You may also use any of these materials for practice. The chapter headings refer to Calculus, Sixth Edition by Hughes-Hallett et al. Published by Wiley such laws to change wealth and power into misery and weakness. SOURCE: Ricardo (1817, pp. 35-40). 26 PART I SOCIAL PROBLEMS, THE SOCIAL WELFARE SYSTEM, AND THE ROLE OF PROFESSIONAL SOCIAL WORK