Practice final for Basic Physics spring 2005 answers on the last page Name: Date:

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1 Practice final for Basic Physics spring 2005 answers on the last page Name: Date: 1. A 12 ohm resistor and a 24 ohm resistor are connected in series in a circuit with a 6.0 volt battery. Assuming negligible internal resistance in the battery, the current in the 12 ohm resistor will be A) 6.0 A. B) 2.0 A. C) 0.50 A. D) 0.25 A. E) A. 2. Which of the following is NOT a vector? A) acceleration B) weight C) mass D) velocity E) All of the above. 3. Which of the following is not an electromagnetic wave? A) Sound B) Microwaves C) Infrared D) X-ray E) Light 4. Neglecting friction, if a Cadillac and Volkswagen start rolling down a hill together, the heavier Cadillac will get to the bottom A) before the Volkswagen. B) after the Volkswagen. C) at the same time as the Volkswagen. 5. Two current-carrying wires are parallel to one another and separated by 1 cm. If the distance between them is increased to 2 cm the new force will be what factor times the original force? A) 4 B) 2 C) 1 D) ½ E) ¼ Page 1

2 6. A parachutist jumping from an airplane reaches a terminal velocity when the force of air resistance is 490 N. The mass of the parachutist is A) 490 kg. B) 9.8 kg. C) 40 kg. D) 50 kg. E) 80 kg. 7. Which of these lists is in order of increasing wavelength? A) First harmonic, second harmonic, third harmonic. B) Second harmonic, third harmonic, fourth harmonic. C) First harmonic, second harmonic, fundamental. D) Third harmonic, second harmonic, first harmonic. 8. An object is placed 15 cm in front of a diverging lens of focal length -10 cm. The image will be located A) cm in front of the lens. B) 3.0 cm behind the lens. C) 3.0 cm in front of the lens. D) 6.0 cm in front of the lens. E) 6.0 cm behind the lens. 9. Comparing the electrostatic force and the gravitational force we can say that A) both have the same dependence on distance, both involve attraction and repulsion but the gravitational force is stronger. B) both have the same dependence on distance, both involve attraction and repulsion but the electrostatic force is stronger. C) both have the same dependence on distance, the electrostatic force can be either attractive or repulsive while the gravitational force is only repulsive, and the electrostatic force is weaker. D) both have the same dependence on distance, the electro static force can be either attractive or repulsive while the gravitational force is only attractive, and the electrostatic force is stronger. E) the electrostatic force falls off more rapidly with distance, the electrostatic force can be either attractive or repulsive while gravitation is only attractive and the electrostatic force is stronger. Page 2

3 10. An elevator is being lifted upward at a constant speed by a steel cable. All frictional forces are neglected. In this situation, forces on the elevator are such that A) the upward force by the cable is greater than the downward force of gravity. B) the upward force by the cable is equal to the downward force of gravity. C) the upward force by the cable is smaller than the downward force of gravity. D) none of the above. (The elevator goes up because the cable is being shortened, not because an upward force is exerted on the elevator by the cable.) 11. Electromagnetic waves are generally A) transverse waves. B) longitudinal waves. C) a 50/50 combination of transverse and longitudinal waves. D) standing waves. 12. Rays from a distant object do not diverge enough for a nearsighted person to focus; this can be corrected with a A) converging or concave lens. B) converging or convex lens. C) diverging or concave lens. D) diverging or convex lens. 13. The temperature of 500 g of water is to be raised from 10 C to 40 C. The energy needed to do this is about A) cal. B) cal. C) cal. D) cal. 14. A true statement about atoms is that they A) can emit radiation only at specific frequencies. B) all have the same number of electrons. C) can emit radiation at any frequency. D) can emit radiation at frequencies only within the visible spectrum. 15. An atom has A) just as many electrons as protons. B) no neutrons in the nucleus. C) more protons than electrons. D) as many electrons as protons and neutrons combined. E) at least 1 neutron. Page 3

4 16. A 1.5 V flashlight battery, a 10 ohm resistor, and a flash light lamp are available. How should the lamp be connected in a circuit so that it would glow the brightest? A) Connect it in series with the resistor and battery so that the bulb is next to the positive terminal of the battery. B) Connect it in parallel with the battery and the resistor. C) Connect it directly to the battery; don't use the resistor. D) Connect it in series with the resistor and battery so that the bulb is next to the negative terminal of the battery. 17. The three processes by which heat energy is transferred between objects are A) heat, calorie and radiation. B) radiation, temperature, and convection. C) absorption, radiation, and convection. D) radiation, convection, and conduction. E) radiation, absorption, and conduction. 18. A quantity that is a measure of how the velocity of a body changes with time is: A) Displacement. B) Speed. C) Acceleration. D) Momentum. 19. The wavelength of a red photon is that of a green photon. A) greater than B) less than C) same as D) greater, same or less, depending on a source of photons 20. A 4 kg block, initially moving due east at 3 m/s, is acted upon by an impulse having magnitude 8 Ns and direction due west. The final velocity of the block is A) 8 m/s west. B) 2 m/s west. C) 1 m/s east. D) 3 m/s east. Page 4

5 21. Which of the following is an appropriate unit for describing rotational acceleration? A) m/s 2. B) rad/min. C) rev/min. D) rev/m/s. E) rev/min Which of the following is not an energy unit? A) N m B) Joule C) calorie D) watt E) kwh 23. The speed of electromagnetic waves in air is 3.0 x 10 8 m/s. What is the wavelength of FM radio waves having a frequency of 1.0 x 10 8 Hz? A) m B) 1.0 m C) 3.0 m D) 6.0 m E) 10 m 24. A rifle bullet is fired horizontally at the same instant another bullet is allowed to drop from rest at the same height. Which bullet strikes the earth first? A) The bullet from the rifle. B) The bullet allowed to drop. C) Both strike at the same instant. 25. Electrons flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside the loop, the direction of this field is A) up. B) down. C) toward the center of the loop. D) radially outward from the center of the loop. Page 5

6 26. A child runs at 4.0 m/s and jumps onto a sled, initially at rest. If the child' mass is 36 kg, and if the child and sled slide off together at 3.0 m/s after the collision, the sled's mass is A) 12 kg. B) 27 kg. C) 36 kg. D) 48 kg. 27. Assuming g = 10 m/s² and that air resistance is negligible, in ½ second a ball dropped from rest will fall A) ½ meter. B) one meter. C) 1.25 meters. D) 5 meters. 28. Magnetic fields affect A) only electric charges at rest. B) only electric charges in motion. C) both electric charges in motion and electric charges at rest. D) neither electric charges in motion nor electric charges at rest. 29. A common property of all waves is the relationship between the speed (v), the wavelength (λ) and the frequency of the wave (f). The correct equation for this relationship is A) f = vλ. B) λ = vf. C) v = fλ. D) v = f / λ. 30. Suppose you climb the stairs of a ten-story building, about 30 m high, and your mass is 60 kg. The gravitational potential energy you gain is about A) 270 Joule. B) 1800 Joule. C) Joule. D) Joule. Page 6

7 31. A heat pump is capable of delivering more energy to the home than goes into the operation of the pump itself, when conditions are favorable. Which of the following statements is correct? A) A heat pump violates the first law of thermodynamics. B) A heat pump violates the second law of thermodynamics. C) A heat pump transfers some energy from the outdoors. D) A heat pump, like the Carnot engine, is a theoretical device that is not useful in practice. E) A heat pump is more efficient when the outside temperature is colder. 32. If your average speed for a 3-hr trip is 45 mi/hr, the distance traveled is A) 15 mi. B) 45 mi. C) 135 mi. D) mi 33. An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to A) an increase in the moment of inertia. B) an increase in the mass. C) an increase in the angular momentum. D) a decrease in the moment of inertia. E) impossible, angular momentum conservation is violated. 34. An iceberg is floating in the ocean with 10% of its volume extending above the ocean's surface. What can you say about the iceberg? A) Its weight is greater than the water it displaces. B) Its density is 90% that of the ocean water. C) It displaces only 90% of its weight in water. D) It must be resting on the bottom, since ice can't float in salt water. 35. A man weighs 600 N while on the surface of Earth. If he is transported to the planet Mythos, which has the same mass as Earth but a radius that is twice as large as Earth's, his weight would be A) 1200 N. B) 600 N. C) 300 N. D) 150 N. E) 100 N. Page 7

8 36. Consider a proton and an electron placed near one another with no other objects close by. They would A) accelerate away from each other. B) remain motionless. C) accelerate toward each other. D) be pulled together at constant speed. E) move away from each other at constant speed. 37. Energy added to a cyclical heat engine A) is completely converted to external work. B) is converted to increased internal energy in the engine plus external work. C) is used to generate work that is greater than the added energy. D) is converted to work and to waste heat. 38. If the image formed by a concave mirror is closer to the mirror than the object is, then compared to the object, the image will be A) larger and inverted. B) smaller and inverted. C) larger and erect. D) larger and real. 39. One section of a pipe carrying water has a cross-sectional area of 20 cm 2 ; in this section the water has flow velocity of 1.0 m/s. Another section of this pipe has a constricted cross-sectional area of 5 cm 2. If the flow is steady, what is the water velocity in the cons tricted section? A) 0.25 m/s B) 0.50 m/s C) 1.0 m/s D) 2.0 m/s E) 4.0 m/s 40. The potential difference across the terminals of a storage battery not connected in any circuit is observed to be 12 V. When it is connected to an external resistance the potential difference across the terminals is observed to be 11 V while the current in the external resistance is 2 A. What is the internal resistance of the battery? A) zero. B) 0.50 ohms. C) 1.0 ohm. D) 2.0 ohms. E) 5.5 ohms. Page 8

9 Answer Key 1. E 2. C 3. A 4. C 5. D 6. D 7. D 8. D 9. D 10. B 11. A 12. C 13. B 14. A 15. A 16. C 17. D 18. C 19. A 20. C 21. E 22. D 23. C 24. C 25. A 26. A 27. C 28. B 29. C 30. C 31. C 32. C 33. D 34. B 35. D 36. C 37. D 38. B 39. E 40. B Page 9