Chapter 20: Work, Energy, Body Temperature and Heat Loss Martin Caon Examination Questions and Answers in Basic Anatomy and Physiology Third Edition

Martin Caon Examination Questions and Answers in Basic Anatomy and Physiology Third Edition Chapter 20: Work, Energy, Body Temperature and Heat Loss 20.1 Work and Energy 1. What is the meaning of “work” in the scientific sense? a. An artist’s completed painting. b. The amount of energy transferred between objects. c. The functions performed during the course of paid employment. d. Sustained physical or mental activity. Answer is B: The amount of work done on an object is the amount of energy transferred to that object. 2. In which of the following cases is the greatest amount of work being done on the object that is experiencing the force? a. 10,000 N is exerted on a wall for 30 s. b. 2000 N is used to raise an object by a height of 10 m. c. 5000 N is used to push an object a distance of 4 m. d. 1000 N is used to pull an object over 50 m. Answer is D: Work = force × distance, so 1000 N × 50 m = 50,000 Nm is the greatest amount. 3. Energy may be defined from the concepts of: a. Force and heat. b. Heat and joules. c. Force and work. d. Work and temperature. Answer is C: When a force causes an object to move, work (in joules) has been done to the object. The work done changes the amount of energy (in joules) stored in an object. 4. Which of the following statements about work is NOT correct? a. More work occurs when a force acts over a small distance (W = F ÷ s). b. Simple machines allow us to perform work more easily. c. Work (done on an object) is the amount of energy that transfers to that object. d. It takes energy to perform work. Answer is A: The reverse is true as: W = F × s. 5. Work is done when an object is moved by a force. What is energy? a. The capacity to do work. b. The rate at which work is done. c. A force that results in no movement. d. The transformation of work from one form to another. Answer is A: Choice B refers to power. Choice C refers to a balanced force. 6. The Système International (Standard International) unit of power is watt. This unit is the same as which one of the following? a. Electronvolt. b. Joule. c. Joule per second. d. Kilojoule. Answer is C: Power is the rate of doing work or of converting energy from one form to another. The unit of power = J/s is renamed the watt in honour of James Watt. All the other choices are units of energy. 7. Which of the following is the most acceptable definition of the term “power”? a. The rate of doing work b. That which is stored and can be fully recovered and converted to kinetic energy c. The concept applied to that which gives an object the ability to do work d. The sum of an object’s potential and kinetic energies Answer is A: Power refers to how fast work is done. That is, the time taken for the energy in joules to be used. The unit of power is “watt” which is the same as joules per second. 8. When a particular energy value is ascribed to a food, what type of energy is being referred to? Its: a. Translational kinetic energy. b. Gravitational potential energy. c. Chemical potential energy. d. Average kinetic energy per molecule. Answer is C: The energy value of food is stored in the chemical bonds within the food molecules. 9. Which one of the following statements best describes what is meant by the “principle of conservation of energy”? a. Internal energy is the sum of kinetic energy, thermal energy and potential energy. b. Energy may be transformed from one form into another, but it cannot be created or destroyed. c. Kinetic energy is gradually transformed into potential energy and vice versa. d. The earth has a finite amount of energy and modern society must learn to use less of it and to use it more efficiently. Answer is B: Energy is noticed when it is transformed from one form to another. However, the total amount when all of its forms are accounted for does not change. 10. A ball initially with 20 J of potential energy has rolled halfway down a slope and is still moving. Which of the following values of kinetic energy (KE) and gravitational potential energy (PE) is it likely to have? a. 0 J of KE and 0 J of PE b. 0 J of KE and 10 J of PE c. 10 J of KE and 10 J of PE d. 10 J of KE and 0 J of PE. Answer is C: The total amount of PE + KE must still be 20 J. As the ball has rolled halfway down the slope, half of its gravitational potential energy has been transformed into kinetic energy. 11. Which one of the following statements does NOT accurately describe energy? a. Energy can be created but not destroyed. b. The total amount of all types of energy remains constant. c. The energy gained by an object is the amount of work done on the object. d. Energy is the heat given out when oxidation occurs. Answer is A: Energy can be neither created nor destroyed.