chap 12
What is the volume of a sugar cube that measures 1 cm on each side? What is the cross-sectional area of the cube? The total surface area?
1 cm3, 1 cm2, 6 cm2
Which is the greater amount for medication measured by mass
1000 milligrams 1 gram both the same
If the linear dimensions of an object are doubled, by how much does the surface area increase? By how much does the volume increase?
4 times, 8 times
A metal block has a mass of 5 grams and a volume of 1 cubic centimeter. A piece of the same kind of metal with a volume of 2 cubic centimeters has a density of
5 g/cm3.
If a 1-kg object stretches a spring by 2 cm, then how much will the spring be stretched when it supports a 3-kg object? (Assume the spring does not reach its elastic limit.)
6 cm
A 1-centimeter cubed sugar cube scaled up by a factor of 10 has a total surface area of
600 cm2.
An un-stretched hanging spring is 50 cm long. Suspending a 100-N block from it increases its length to 60 cm. Adding another 100-N block makes the spring's length
70 cm.
How do you explain the saying "The bigger they are, the harder they fall" using scaling?
A big creature has a small ratio of surface area to mass, so air resistance doesn't slow it as much when it falls.
What is meant by the elastic limit for a particular object?
A spring is elastic up to the limit and inelastic above it.
Which of the following has the greatest outer surface area?
An elephant
If you want to light some wood on fire, what would most likely make the wood light, and why?
Breaking the log down into small pieces of wood will increase the amount of wood surface that can catch fire.
If you want to cool down a drink with ice, which of the following would make it cool faster and why?
Crushing the lump into small pieces will put more of the ice's surface area is in contact with the drink.
What type of force holds atoms together in a crystal?
Electric
Which has more skin: an elephant or a mouse? Which has more skin per unit of body weight: an elephant or a mouse?
Elephant, mouse
Which requires more food daily: an elephant or a mouse? Which requires more food per unit of body weight: an elephant or a mouse?
Elephant, mouse
How does the ratio of surface area to volume change if you increase the length of the side?
It decreases.
How does the cross-section area will change when you increase the length of the side from 1 cm to 2 cm, to 3 cm, and then to 4 cm?
It increases by a factor of 22, by a factor of 32, and then by a factor of 42.
How does the volume change when you increase the length of the side from 1 cm to 2 cm, to 3 cm, and then to 4 cm?
It increases by a factor of 23, by a factor of 33, and then by a factor of 43.
Which of these is most elastic?
Steel
What is Hooke's law? Does it apply to elastic materials or to inelastic materials?
Stretch is proportional to force for elastic materials
What and where is the neutral layer in a beam that supports a load?
The layer in which there is neither tension nor compression along the middle from end to end
Which of the following items would remain without rusting longer: a solid lump of steel, or steel wool that weighs the same amount?
The lump of steel would stay without rusting longer, because not as much of it comes in contact with the air.
Why aren't vertical columns needed to support the middle of domed stadiums, such as the Houston Astrodome?
The weight produces compression that supports the dome.
Why do French fries cook faster when they are cut into thinner pieces, and why do meatballs cook faster when they are flattened?
There is a greater amount of surface area for the same amount of food in the thinner fries and flattened meatballs.
Which is denser: an object that has a density of 1000 kg/m3 or one that has a density of 1 g/cm3?
They are the same density
Why are the cross-sections of metal beams in the shape of the letter I instead of solid rectangles?
To reduce the weight of the beam while preserving the resistance to bending
Why do we say that a spring is elastic?
When deformed, it returns to its original shape.
The first evidence confirming the crystal structure of matter was
X-ray diffraction patterns.
Which has more volume, a kilogram of gold or a kilogram of aluminum?
a kilogram of aluminum
Which has more mass, a liter of ice or a liter of water?
a liter of water
Which has more skin compared to its body weight?
a mouse
Which potato cooks faster in boiling oil?
a sliced potato.
Compared with a solid steel bar having a rectangular cross-section, an I-beam has the advantage of
both of these
The Gateway Arch in St. Louis, Missouri, is a
catenary.
When the curve of a vertical structure matches the inverted image of a drooping chain held at both ends, the curve is called a
catenary.
The metal in a chunk of copper or iron is composed of
crystals.
The effects of scaling are beneficial to swimmers in a race who are relatively
large.
To make taffy apples, a candymaker buys 100 kg of large apples rather than 100 kg of small apples. That means she will need
less taffy.
Compared to the volume of a kilogram of feathers, the volume of a kilogram of lead is
less.
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
less.
A horizontal wooden beam sags a bit when supported at its ends. In between the top and bottom surfaces is a region of
neither of these
A beam is under stress when it carries a load. The part of a beam where no tension or compression occurs is the
neutral layer.
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
only four times as much.
If you bake cupcakes as directed for a cake, the cupcakes will be
over-baked.
When a chocolate bar is cut in half, its density is
unchanged.
