Academic Year 2016-2017 First Term Science Revision sheets PHYSICS ( Answer key ) Name: Grade: 10 Date: Section: (A) Science Practice : Q1: Choose the letter of the choice that best answer the questions: 1. What term is defined as the energy transferred between objects with different temperatures? a. internal energy b. work c. heat d. thermal equilibrium 2. Which of the following is proportional to the average kinetic energy of particles in matter? a. heat b. temperature c. thermal equilibrium d. internal energy 3. The temperature of the air is measured as 235 K. What is this temperature equal to in degrees Celsius? a. 508 C b. 203 C c. 38 C d. 68 C 1

4. If energy is transferred spontaneously as heat from a substance with a temperature of T1 to a substance with a temperature of T2, which of the following statements must be true? a. T1 < T2 b. T1 = T2 c. T1 > T2 d. More information is needed. 5. Which of the following statements best describes a state of thermal equilibrium between two systems? a. Both systems have the same mass. b. Both systems have the save volume. c. Both systems have the same temperature. d. Both systems contain the same amount of internal energy 6. What is the process by which energy is transferred by the motion of cold and hot matter? a. thermal conduction b. thermal insulation c. convection d. radiation 7. The use of fiberglass insulation in the outer walls of a building is intended to minimize heat transfer through what process? a. conduction c. convection b. radiation d. vaporization 8. Which of the following is proportional to the kinetic energy of atoms and molecules? a. elastic energy c. potential energy b. temperature d. thermal equilibrium 2

9. As the temperature of a substance increases, its volume tends to increase due to a. thermal equilibrium. c. thermal expansion. b. thermal energy. d. thermal contraction 10. Energy transferred as heat occurs between two bodies in thermal con-tact when they differ in which of the following properties? a. mass c. density b. specific heat d. temperature 11. What is the quantity of energy needed to raise the temperature of a unit mass of a substance by 1 C called? a. latent heat c. specific heat capacity b. internal energy d. thermal energy 12. Which of the following are ways in which energy can be transferred to or from a substance? a. heat and internal energy c. work and internal energy b. heat and work d. heat and kinetic energy 13. What is a set of particles or interacting components that is considered a distinct physical entity called? a. an engine c. a system b. an environment d. an ideal gas 14. What temperature has the same numerical value on both the Celsius and the Fahrenheit scales? a. 40 c. 40 b. 0 d. 72 3

15. Which temperature scale is used widely in science, and is applied to nonscientific uses throughout most of the world? a. Celsius c. Rankine b. Fahrenheit d. Kelvin 16. What term is defined as the energy transferred between objects with different temperatures? a. internal energy c. work b. heat d. thermal equilibrium 17. What must be true if energy is to be transferred as heat between two bodies in physical contact? a. The two bodies must have different volumes. b. The two bodies must be at different temperatures. c. The two bodies must have different masses. d. The two bodies must be in thermal equilibrium. 18. During a phase change, which of the following properties does not change? a. internal energy c. physical state b. temperature d. volume 19. If energy is transferred from a table to a block of ice moving across the table, which of the following statements is true? a. The table and the ice are at thermal equilibrium. b. The ice is cooler than the table. c. The ice is no longer 0 C. d. Energy is being transferred from the ice to the table. 4

20. If there is no change in the internal energy of a gas, even though energy is transferred to the gas as heat and work, what is the thermodynamic process that the gas undergoes called? a. adiabatic c. isothermal b. isovolumetric d. isobaric II. Fill in the blanks : [ isothermal, work, adiabatic, isovolumetric, system, pressure, 273.15, thermometer, absolute zero, heat ] 1. System is a set of particles or interacting components considered to be distinct physical entity for the purpose of study. 2. Pressure is a measure of how much force is applied over a given area. 3. A thermodynamic process that takes place at constant volume so that no work is done on or by the system is called Isovolumetric process. 4. Thermodynamic process that takes place at constant temperature is called Isothermal process. 5. In a thermodynamic process no energy is transferred to or from the system as heat is called Adiabatic process. 6. For gases at constant pressure, Work is defined as the product of gas pressure and the change in the volume of gas. 7. Thermal equilibrium is the basis for measuring temperature with Thermometer 8. T = Tc + 273.15 9. The temperature of 0 K is often referred as. Absolute zero 5

10. Heat is the energy transferred between objects because of a difference in their temperature. III. State whether the statement is True or False : 1. When the gas volume remains constant, there is no displacement and no work is done on or by the system. True 2. During adiabatic process, the temperature of the system does not change. False 3. Isovolumetric process takes place inside a bomb calorimeter. True 4. All the object have internal energy, which is the sum of kinetic and potential energies of their molecules. True 5. A temperature difference of one degree is the same on the Celsius and Kelvin scale. True 6. Energy is transferred as heat from the lower energy particles to a higher energy particles. False 7. Heat is indicated by the symbol Q. True 8. Potential energy is the energy of an object due to its motion. False 9. T = Tc + 32.0 False 10. The net energy transferred is zero when the thermal equilibrium reached. True 6

IV. Match the following : A Answ er B 1. Temperature d a temperature does not change 2. Isovolumetric f b zero 3. Isothermal a c combination of substances 4. Work g d. Average kinetic energy 5. PE + KE + U b e without changing temperature 6. System c f a steel tank of gas being heated 7. Specific heat capacity h g pressure x volume change 8. Phase change e h calorimeter V. Answer the following : 1. What happens to the temperature and internal energy of the gas and water after the combustion reaction? The water s temperature and internal energy increases as the gas s temperature and internal energy decreases. 2. What will happen when we hold our hands apart after vigorously rubbing our hands? Explain. Hands cool off ;Energy is transferred as heat from the hands to the air. 3. In what ways can the internal energy of a system be increased? Energy transfers to the system as heat or as work. 4. When an ideal gas expands adiabatically, it does work on its surrounding. Describe the various transfers of energy that take place. 7

Work done by gas cause a decrease in U and T ( temperature ) of gas and an increase in U of surroundings. 5. A hot copper pan is dropped into a tub of water. If the water s temperature rises, what happens to the temperature of the pan? How will you know when the water and copper pan reach thermal equilibrium? 6. Is there more mercury in the tube at 50 0 C than there is at 0 0 C? No, because of thermal expansion, the same amount of merury occupied a larger volume at 500C 7. A pan of water is heated from 230C to 780C. What is the change in its temperature on the Kelvin and Fahrenheit scales? 8

Bonus questions: 1. Paint from and aerosol can is sprayed continuously for 30 s. The can was initially at room temperature, but now it feels cold to touch. What type of thermodynamic process occurs for a small sample of gas as it leaves the high pressure interior of the can and moves to the outside atmosphere? Adiabatic 2. One day it was 40 0 C at the top of Mont Blance and 40 0 F at the top of Mount Whitney. Which place was colder? Neither ( - 40 0 C = - 40 0 F ) 3. A pan of water is heated from 230C to 780C. What is the change in its temperature on the Kelvin and Fahrenheit scales? 9