DATE: NAME: CLASS: BLM 6-8 ASSESSMENT. Multiple Choice Circle the letter for the choice that best completes the statement or answers the question.

Transcription

1 Unit 2 Test Goal Demonstrate your understanding of the information presented in Unit 2. What to Do Carefully read the instructions before answering each set of questions. Multiple Choice Circle the letter for the choice that best completes the statement or answers the question. 1. Who designed the first practical steam engine with a piston that moved up and down in a cylinder? (a) Savery (b) Newcomen (c) Watt (d) Joule 2. Who designed the first steam engine that was not dependent on atmospheric pressure? (a) Savery (b) Newcomen (c) Watt (d) Joule 3. Which of the following still use steam pressure? (a) textile factories (b) farm tractors (c) train locomotives (d) ocean liners 4. How does a steam turbine differ from the earlier steam engines? (a) Steam is generated inside the turbine. (b) A steam turbine does not have pistons and cylinders. (c) Water is sprayed into a turbine to condense the steam. (d) The two machines are basically the same, but the steam turbine is more efficient. 5. According to the phlogiston theory of heat: (a) Many objects contain a substance called phlogiston that flows out of the object when it burns. (b) Phlogiston is a massless fluid that flows into an object and makes the object warm. (c) Phlogiston is the substance that burns when something is on fire. (d) Phlogiston is a form of energy. 6. Which observation refutes the phlogiston theory? (a) When magnesium burns, the ashes have a larger mass than the original magnesium. (b) When boring holes in metal cylinders to make cannons, the metal becomes extremely hot. (c) When water is stirred vigorously, it becomes warmer. (d) Sailors in the tropics have bright red blood in their veins.

2 7. Who was originally given credit for demonstrating the mechanical equivalent of heat? (a) Count Rumford (b) Julius Mayer (c) James Joule (d) William Thomson 8. When using the formula for work, the direction of the force and the direction of the motion that is caused by the force must be (a) parallel (b) perpendicular (c) opposite (d) unrelated 9. According to the kinetic-molecular theory of heat, which statement is not true? (a) Thermal energy is the motion of atoms and molecules in a substance. (b) As the speed on the atoms and molecules increases, the object becomes hotter. (c) When atoms and molecules collide, they transfer energy to each other. (d) Since atoms in a solid cannot move away from the adjacent atoms, they cannot move faster when thermal energy is added to the solid. 10. Which statement is not included in a statement of the first law of thermodynamics? (a) Energy cannot be created or destroyed. (b) Energy can be transformed from one type to another. (c) Energy can be transferred from one object to another. (d) Thermal energy always flows from a warmer object to a cooler object. 11. Which method of generating electrical energy is used the least in Canada? (a) coal-burning (b) nuclear reactors (c) hydro-electric (d) gas-turbine 12. Which of the following quantities is a scalar quantity? (a) speed (b) velocity (c) acceleration (d) displacement 13. Which of the following quantities is a vector quantity? (a) time interval (b) distance (c) work (d) velocity

3 14. Which statement correctly describes the relationship between distance and displacement between two specific points. (a) Distance is always equal to the magnitude of the displacement. (b) Distance is always greater than the magnitude of the displacement. (c) Distance is never equal to the magnitude of the displacement. (d) Distance is sometimes equal to the magnitude of the displacement. 15. Which quantity depends on the path that is taken between two points. (a) distance (b) displacement (c) velocity (d) acceleration 16. Which statement about a graph of displacement versus time is not true? (a) A horizontal line indicates that the object was standing still. (b) A downward slope of a straight line indicates that the object was slowing down. (c) An upward slope of a straight line indicates that the object was moving at a constant velocity. (d) An upward curving line indicates that the object was accelerating. 17. Which statement about the relationship between work and kinetic energy is not true? (a) When a force does work on an object, the object might gain kinetic energy. (b) When a force does work on an object, the object might lose kinetic energy. (c) When a force does work on an object, the object always gains kinetic energy. (d) When a force does work on an object, the object might have no change in its kinetic energy. 18. Elastic potential energy can be stored in any object that (a) can be stretched when pulled (b) will return to its original form when released (c) can be compressed squeezed (d) will take on any shape when under pressure 19. The weight of an object is (a) the same as its mass (b) the force of gravity acting on its mass (c) not related to its mass (d) any force acting on its mass 20. The thermal energy that is released when a large nucleus fissions (a) is the kinetic energy of the fission products (the smaller nuclei that result from the splitting of the large nucleus) (b) is the chemical energy of the fission products (c) is the kinetic energy of the unstable large nucleus (d) is the mass of the fission products

4 21. The useful output energy of a motor is (a) sound (b) heat (c) light (d) kinetic energy 22. Which statement about the motion of a pendulum is not true? (a) All the energy is gravitational potential energy at the top of the swing. (b) All the energy is gravitational potential energy at the bottom of the swing. (c) All the energy is kinetic energy at the bottom of the swing. (d) The energy is partly gravitational potential energy and partly kinetic energy between the top and bottom of the swing. 23. Which device or machine is typically the most efficient? (a) motor (b) automobile (c) light bulb (d) The efficiencies of the devices or machines are too similar to compare. 24. Which statement about hydro-electric generators is not true? (a) They are very energy efficient. (b) Their upkeep is expensive. (c) They are very costly to build. (d) They can be a threat to some endangered species. Numerical Response Record the answer to each numerical-response question as indicated. 25. Imagine that you carry a box of books, weighing 67.8 N, up a flight of stairs. If each step is 15.0 cm high, and there are 22.0 steps in the flight of stairs, how much work do you do on the box of books? Record your threedigit number in the numerical-response box. 26. A jackrabbit can reach a velocity of m/s from a resting position in 1.25 s. What is the rabbit s acceleration? Record your three-digit number and decimal point in the numerical-response box. 27. While riding up a chair lift, a 54.8 kg skier gains J of gravitational potential energy. The top of the ski lift is what vertical distance above its base? Record your three-digit number in the numerical-response box.

5 28. In a toy, a 92.4 g ball rolls into a spring and compresses the spring. If the ball is rolling at 4.28 m/s when it collides with the spring and, at maximum compression, the spring is storing J of elastic potential energy, with what efficiency is the ball s kinetic energy converted into elastic potential energy of the spring? Record your three-digit number and decimal point in the numerical-response box. % Long Answer Answer the following question in the space provided. Be sure to use complete sentences. 29. Describe the three main sources of electrical energy in Canada. Include the relative efficiency of each source. Explain the most serious threat that each type of electrical generating station poses to the environment.