Q&A Hero

Q: Which will remain the same for two identical books, one lying flat and the other standing on an end? A) weight B) pressure C) both of these D) neither of these

Q: The concept of pressure involves both A) force and volume. B) force and area. C) area and volume.

Q: Surface tension of liquids A) increases when wetting agents are added. B) decreases as the liquid temperature increases. C) is about the same for all liquids. D) results from a thin molecular membrane beneath the liquid surface. E) keeps steel ships afloat.

Q: A very lightweight horizontal loop of wire is suspended from a fine spring, lowered into water, and then raised to the surface. Any further attempt to raise it causes the spring to A) stretch. B) contract. C) stay the same.

Q: Surface tension is a direct result of A) viscosity. B) Archimedes' principle. C) adhesive forces between molecules in a liquid or solid. D) cohesive forces between molecules in a liquid.

Q: When you place a stick in water and remove it, the stick is wet. If you instead place it in mercury the opposite occurs. The stick is dry. This is because adhesive forces are greater A) between stick and water. B) between the stick and mercury. C) between the mercury and the water. D) none of the above

Q: A consequence of surface tension for water is A) capillary action. B) wet sand being firmer than dry sand. C) the different tastes of hot and cold oily soup. D) all of the above E) none of the above

Q: The attraction between unlike substances is called A) adhesion. B) cohesion. C) depends on the substances.

Q: The attraction between like substances, stickiness, is called A) adhesion. B) cohesion. C) depends on the substances.

Q: A hydraulic press multiplies a force by 100, which is done at the expense of A) energy, which is divided by 100. B) the distance through which the force acts. C) the time through which the force acts. D) the mechanism providing the force. E) none of the above

Q: To multiply an applied force while using a simple hydraulic lift, your force should be applied to the A) large-diameter piston. B) small-diameter piston. C) relative piston sizes don't matter.

Q: In a hydraulic-press operation, it is impossible for the A) output displacement to exceed the input displacement. B) force output to exceed the force input. C) energy output to exceed the energy input. D) output piston's speed to exceed the input piston's speed. E) none of the above

Q: When you observe the applications of pistons in lifting operations you're seeing A) Pascal's principle in action. B) how energy can be increased. C) both of these D) neither of these

Q: Pascal's principle applies to A) liquids. B) gases. C) both of these D) none of these

Q: The pascal is a pressure unit equal to A) 1 newton per square meter. B) 1 kilogram per square meter. C) 1 newton per square centimeter. D) 1 kilogram per square centimeter.

Q: A block of wood with a piece of iron tied to the top of it floats in a bucket of water. If the wood and iron are turned over so that the iron is submerged beneath the wood, the water level at the side of the bucket A) rises. B) falls. C) remains the same.

Q: If a weighted air-filled balloon sinks in deep water, it will A) likely sink to an equilibrium level before reaching bottom. B) likely burst if water pressure is great enough. C) be acted on by a continuously decreasing buoyant force. D) none of the above

Q: If the part of an iceberg that extends above the water were suddenly removed, the A) iceberg would sink. B) buoyant force on the iceberg would decrease. C) density of the iceberg would change. D) pressure on the bottom of the iceberg would increase. E) none of the above

Q: If a battleship sinks in a canal lock, the water level in the lock will A) rise. B) fall. C) remain unchanged.

Q: When a load of wood is thrown overboard from a boat in a swimming pool, the pool level A) rises. B) falls. C) remains unchanged.

Q: When a barrel of water in a rowboat in a swimming pool is poured overboard, the pool level A) rises. B) falls. C) remains unchanged.

Q: When scrap iron in a boat is thrown overboard in a swimming pool, the pool level A) rises. B) falls. C) remains unchanged.

Q: A heavy iron ball is placed in an aluminum pie pan that floats in a bucket. The water level at the side of the bucket is marked. Then the ball is removed and allowed to sink in the bucket. The water line at the side of the bucket A) goes down. B) is the same. C) rises.

Q: When a large floating ice cube with unfrozen water inside melts, the water level in its container A) goes down. B) remains unchanged. C) goes up.

Q: A floating ice cube contains small pieces of iron. The water level after melting will A) rise. B) fall. C) remain unchanged.

Q: A large ice cube containing an iron railroad spike floats in a brim-full container of water. When the ice cube melts, A) water spills over. B) no change in water level occurs. C) water level in the container drops.

Q: An ice cube with large air bubbles in it floats in a brim-full container of water. When the ice cube melts, A) water spills over. B) no change in water level occurs. C) water level in the container goes down.

Q: An ice cube floating in a glass of water contains many air bubbles. When the ice melts, the water level will A) rise. B) fall. C) remain unchanged.

Q: When an ice cube in a glass of water melts, the water level A) rises. B) falls. C) remains the same.

Q: A person floats higher in the dense water of the Dead Sea because A) less volume of water is displaced. B) more volume of water is displaced. C) of a greater buoyant force.

Q: When you float in fresh water, the buoyant force that acts on you is equal to your weight. When you float higher in the denser water of the Dead Sea, the buoyant force that acts on you is A) greater than your weight. B) less than your weight. C) equal to your weight.

Q: The amount of water displaced by a liter-sized block of ordinary wood floating in water is A) less than 1 liter. B) 1 liter. C) more than 1 liter. D) depends on the water density E) none of the above

Q: An important condition for operation of the Falkirk Wheel is that A) water in each gondola have the same depth. B) ships carried are more or less equal in weight. C) no water spill when a ship enters a gondola. D) all of the above E) none of the above

Q: Consider the fictional case of the incredible shrinking woman. If a fictional shrinking woman shrinks to 0.1 her original height, her total skin area shrinks to A) 0.1 times its original value. B) 0.01 times its original value. C) 0.001 times its original value. D) 0.0001 times its original value. E) none of the above

Q: If a fictional shrinking man shrinks proportionately to 1/10 his original height, his weight will be multiplied by A) 0.1. B) 0.01. C) 0.001. D) 0.0001. E) none of the above

Q: The larger a turkey cooked in a conventional oven at a given temperature, the A) more time per pound is needed. B) less time per pound is needed. C) the same time per pound is needed.

Q: Eight little spheres of mercury coalesce to form a single sphere. Compared to the combined surface areas of the eight little spheres, the surface area of the big sphere is A) one eighth. B) one quarter. C) one half. D) the same. E) double.

Q: Eight little spheres of mercury coalesce to form a single sphere. Compared to the combined surface areas of the eight little spheres, the surface area of the big sphere is A) less. B) the same. C) greater.

Q: If you bake cupcakes as directed for a cake, the cupcakes will be A) over-baked. B) under-baked. C) properly baked.

Q: The effects of scaling are beneficial to swimmers in a race who are relatively A) large. B) small. C) neither of these

Q: Compared to a 50-kg person, a 100-kg person at the beach requires A) twice as much suntan lotion. B) the same amount of suntan lotion. C) less than twice as much suntan lotion.

Q: A solid glass ball weighs 1 N. One with twice the diameter weighs A) 1 N. B) 2 N. C) 3 N. D) 4 N. E) more than 4 N.

Q: Tripling the linear size of an object multiplies its area by A) 3 and its volume by 9. B) 9 and its volume by 18. C) 9 and its volume by 27. D) 27 and its volume by 81. E) none of the above

Q: If each dimension of a steel bridge is scaled up ten times, its strength will be multiplied by about A) ten and its weight by ten also. B) one hundred, and its weight by one thousand. C) one thousand, and its weight by one hundred thousand. D) none of the above

Q: In cold weather, your hands will be warmer if you wear A) gloves. B) mittens. C) both the same

Q: A dome-shaped house is more heat efficient than a rectangular house because a dome has A) no corners to radiate. B) less interior space. C) less area compared to its volume. D) all of the above E) none of the above

Q: When a living cell doubles in diameter, it has eight times the mass to be nourished, and the amount of membrane through which it feeds is A) only twice as much. B) only four times as much. C) also eight times as much. D) more than eight times as much.

Q: The effects of scaling are beneficial to small creatures A) that get wet. B) that fall from great heights. C) who are hungry. D) all of the above E) none of the above

Q: Which potato cooks faster in boiling oil? A) a whole potato. B) a sliced potato. C) both the same

Q: An elephant radiates less heat for its size than smaller animals because A) its radiating area is small compared to its volume. B) its radiating area is large compared to its volume. C) it is taller than smaller animals. D) it weighs more than smaller animals.

Q: If an elephant grows proportionally to twice its height, its weight would be multiplied by about A) 2. B) 4. C) 6. D) 8. E) none of the above

Q: If an elephant grows proportionally to twice its height, the area of its ears would be about A) twice. B) four times more. C) six times more. D) eight times more. E) none of the above

Q: To make taffy apples, a candymaker buys 100 kg of large apples rather than 100 kg of small apples. That means she will need A) less taffy. B) more taffy. C) the same amount of taffy.

Q: Suppose you put a chocolate layer on pieces of candy. Compared with the amount of chocolate used to cover 1 pound of large pieces, if you cover 1 pound of smaller pieces you'll use A) less chocolate. B) the same amount of chocolate. C) more chocolate. D) makes no difference

Q: Which potatoes when peeled produce the most peelings? A) 10 kg of large potatoes B) 10 kg of small potatoes C) both the same

Q: One kilogram of peaches has more skin area than one kilogram of A) blueberries. B) grapefruits. C) grapes. D) all of the above

Q: Doubling the linear size of an object multiplies its area by A) 2 and its volume by 4. B) 4 and its volume by 8. C) 8 and its volume by 16. D) none of the above

Q: The weight of a 1-centimer cubed metal cube scaled up by a factor of 10 will be A) ten times as much. B) a hundred times as much. C) a thousand times as much. D) none of the above

Q: A 1-centimeter cubed sugar cube scaled up by a factor of 10 has a total surface area of A) 60 cm2. B) 600 cm2. C) 6000 cm2. D) none of the above

Q: A 1-centimeter cubed sugar cube scaled up by a factor of 10 has a volume of A) 10 cm3. B) 100 cm3. C) 1000 cm3. D) none of the above

Q: If a pencil's length and diameter are both multiplied by 10, then its volume is multiplied by A) 10. B) 100. C) 1000. D) 10,000. E) none of the above

Q: A creature that is scaled up in size, keeping its proportions, A) will be stronger relative to its greater weight. B) will be weaker relative to its greater weight. C) both of these D) neither of these

Q: Lillian sees a chair at the Exploratorium that has been scaled up by three. In attempting to lift it, she finds the chair is A) three times as heavy. B) six times as heavy. C) nine times as heavy. D) more than nine times as heavy.

Q: Which geometrical shape has the least surface area for a given volume? A) cube B) pyramid C) cylinder D) sphere E) none of the above

Q: Flatten a spherical meatball into a hamburger and you increase its A) surface area. B) volume. C) both of these D) none of these

Q: Which has more skin compared to its body weight? A) an elephant B) a mouse C) both the same

Q: Which has more skin? A) an elephant B) a mouse C) both the same

Q: An athlete can perform a certain number of pushups. The same athlete scaled up in size can do A) fewer pushups. B) the same number of pushups. C) more pushups.

Q: The strength of a beam is most related to its A) cross section. B) length. C) both of these

Q: Support a horizontal toothpick at both ends. Then do likewise for a log of the same kind of wood. There is more sag in the A) toothpick. B) log. C) same in each

Q: A catenary in nature is evident in A) eggs. B) a necklace drooping between your fingers. C) the domes of some modern buildings. D) all of the above

Q: The Gateway Arch in St. Louis, Missouri, is a A) parabola. B) hyberbola. C) catenary.

Q: When the curve of a vertical structure matches the inverted image of a drooping chain held at both ends, the curve is called a A) parabola. B) hyperbola. C) catenary.

Q: When a load is placed on a properly arched structure, compression A) weakens the structure. B) strengthens the structure. C) neither of these

Q: When weight is applied to the top of a stone arch, the stone blocks in the arch undergo A) tension. B) compression. C) expansion. D) none of the above

Q: Doubling the thickness (diameter) of a rope will multiply its strength by A) 1/2. B) 1. C) 2. D) 3. E) 4.

Q: The strength of a rope depends on its A) thickness. B) length. C) both of these

Q: Stone slabs are stronger under A) tension. B) compression. C) both of these D) none of these

Q: You wish to drill a hole through a horizontal I-beam supporting a bridge. To weaken the beam the least drill the hole through the A) upper flange. B) lower flange. C) web. D) all the same

Q: Compared with a solid steel bar having a rectangular cross-section, an I-beam has the advantage of A) being lighter. B) being stronger per bodyweight. C) both of these D) neither of these