Chapter 12: Solids

Question 1

Muller’s micrograph, shown in the chapter-opener photo reveals

Answer 1

the positions of atoms.

Question 2

The crystals that make up minerals are composed of

Answer 2

atoms with a definite geometrical arrangement.

Question 3

The crystals that make up minerals are composed of

Answer 3

atoms with a definite geometrical arrangement.

Question 4

Atoms in a crystal are held together by

Answer 4

electrical bonding forces.

Question 5

Which of these has the greatest density: 10 kg of concrete, 2 kg of concrete, 3 kg of iron or 1 g of lead?

Answer 5

1 g of lead

Question 6

When a given mass of water freezes, it undergoes a

Answer 6

decrease in density.

Question 7

An elastic material is one in which

Answer 7

original shape is restored when a deforming force is removed.

Question 8

According to Hooke’s law, if you hang by a tree branch and note how much it bends, then hanging with twice the weight normally produces

Answer 8

twice the bend.

F ~ ∆x; so twice the F means twice the ∆x.

Question 9

A pair of vertical springs, side-by-side, equally support a 20-N load. If the load is doubled and the elastic limit of the springs is not reached, then the tension in each spring will be

Answer 9

20 N. Tension in each spring supporting the 20 N load will be 10 N. Doubling the load doubles each tension to 20 N.

Question 10

When you sit in the middle of a horizontal bench supported at its ends, the top side of the bench is

Answer 10

compressed and the bottom is stretched.

Question 11

The shape that has the greatest strength in construction is the

Answer 11

triangle.

Question 12

Opposite flanges in a properly positioned horizontal I-beam supported at each end undergo

Answer 12

compression in the top and tension in the bottom flange.

Question 13

Most of the stone arches built by people in ancient times took the shape of a

Answer 13

semicircle

Question 14

The catenary idea was central in the design of the

Answer 14

Gateway Arch in St. Louis.

Question 15

Which of these has more combined surface area: 1 kg of grapes, 1 kg of raisins, 1 kg of potatoes, 1 kg of squash?

Answer 15

1 kg of raisins

Question 16

Suppose you scale up a model machine by a factor of 3. Then its volume is

Answer 16

27 times as much and its surface area is 9 times as much.

Remember the rule: When something is scaled upward, area increases as the square of the increase (3^2 in this case) and volume as the cube of the increase (3^3).

Question 17

When you scale up an object to four times its linear size, the surface area increases by

Answer 17

16 and the volume by 64. When something is scaled upward by 4, area increases as the square of the increase, 4^2 = 16, and volume by the cube, 4^3 = 64.

Question 18

Four small spheres of mercury coalesce to form a single sphere. Compared with the combined surface area of the smaller spheres, the surface of the big sphere is

Answer 18

less.

Question 19

If Alice in Wonderland shrinks to one-tenth her size, the ratio of her surface area/volume will

Answer 19

increase. Although both her surface area and volume decrease, there is great decreases in the volume, hence the ratio surface area/volume increases.

Question 20

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.

Answer 20

b) that fall from great heights.

Question 21

The linking together of atoms to form larger structures, including solids.

Answer 21

Atomic bonding

Question 22

The mass of a substance per unit volume.

Answer 22

Density
density = mass / volume

Weight density is weight per unit volume:
Weight density = weight / volume

Question 23

The amount of stretch or compression of an elastic material is directly proportional to the applied force.

Answer 23

Hooke’s law

Question 24

The study of how size affects the relationships among weight, strength, and surface.

Answer 24

Scaling