Part 3 — Questions 41 to 60
41. A perpetual motion machine can never be built because it is not possible to eliminate:
Correct Answer: D) Friction
Friction dissipates usable energy, preventing a machine from running forever without input.
42. Waves bend when they move around obstructions or pass through narrow openings. This type of bending is called:
Correct Answer: C) Diffraction
Diffraction is when waves spread out around obstacles or through gaps.
43. A sudden net force of 15 N is applied to an object that starts at rest and reaches 12 m/s in 4 seconds. What is the mass of the object?
Correct Answer: B) 5 kg
Acceleration a = Δv/Δt = 12/4 = 3 m/s². Using F = ma, m = F/a = 15/3 = 5 kg.
44. Our lungs convey __________ to blood cells and receive __________ and __________ from blood cells.
Correct Answer: A) oxygen, carbon dioxide, water
Lungs bring oxygen into blood and remove carbon dioxide and water vapor from blood.
45. If the tire of a car rotates at 552 times in one minute, how many times in half an hour?
Correct Answer: D) 16,560
Half an hour is 30 minutes. Multiply rotations per minute by 30: 552 × 30 = 16,560.
46. A sales manager buys antacid in bottles by the gross. If he goes through 3 bottles every day, how long will the gross last?
Correct Answer: D) 48 days
A gross equals 144 items. 144 ÷ 3 = 48 days.
47. A waitress earns an average of 12% of the cost of the food she serves. If she serves $375 worth of food, how much tip does she earn?
Correct Answer: B) $45
12% of $375 is 0.12 × 375 = $45.
48. How many square feet of carpeting are needed for a 12 foot by 12 foot room?
Correct Answer: D) 144
Area = length × width = 12 × 12 = 144 square feet.
49. The ratio 36:12 simplified is:
Correct Answer: B) 3:1
Divide both numbers by 12: 36/12 = 3, 12/12 = 1, so 3:1.
50. If x + y = 2 and x − y = 1, then x and y are:
Correct Answer: C) x=3/2, y=1/2
Add equations: 2x = 3 → x = 3/2. Substitute to find y = 1/2.
51. What is the value of sqrt(3^2)?
Correct Answer: A) 3
Square root and square cancel: sqrt(3^2) = sqrt(9) = 3.
52. Antagonize most nearly means:
Correct Answer: C) Provoke
To antagonize is to provoke hostility.
53. Wilted most nearly means:
Correct Answer: B) Limp
Wilted describes something limp or drooping, usually from loss of water.
54. His record provides no reason for apprehension. The best synonym for apprehension is:
Correct Answer: A) Anxiety
Apprehension means worry or anxiety.
55. Quiver most nearly means:
Correct Answer: A) Shake
Quiver is a small, rapid shake or tremble.
56. What does the abbreviation AC stand for?
Correct Answer: B) Alternating current
AC is current that periodically reverses direction, unlike DC.
57. What is measured using an ohmmeter?
Correct Answer: B) Resistance
An ohmmeter measures electrical resistance in ohms.
58. A circuit with 120 volts and a 5 amp breaker. What is the largest number of watts an appliance on this circuit can safely use?
Correct Answer: A) 600 W
Power P = V × I. So P = 120 V × 5 A = 600 W.
59. In household wiring, which color indicates the hot wire?
Correct Answer: C) Black
In common US wiring black is typically the hot conductor. Green is ground.
60. The radiator on a car is part of the:
Correct Answer: A) Cooling system
The radiator removes heat from engine coolant to keep engine temperature safe.