A square plane mirror of side length s s hangs on a wall such that its bottom edge is a height h h above the floor. The wall opposite the mirror is a distance d d away. Marco, whose eyes are at the exact height of the center of the mirror, stands directly in front of the mirror at the center of its width. Derive an expression for the maximum distance x x that Marco can stand from the mirror and still see the reflection of the bottom of the wall behind him. Assume that s < 2 h .

Classify the following soils according to the uscs classification system. provide appropriate uscs designations. a) this sample of well-graded gravel with sand was obtained from a large earthen dam in vancouver, canada. the sample has 73% fine to coarse sub-angular gravel, 25% fine to coarse sub-angular sand and 2% fines. the maximum size of the particles is 75 mm. the coefficient of curvature is 2.7, while the uniformity coefficient is 12.4. b) this dark brown and wet soil with a “strong organic odor” has 100% passing the no. 200 sieve. the liquid limit of the material is 32% when not dried and is 21% when oven-dried. the plastic index is 21% when not dried. c) this sand has 61% predominantly fine sand, 23% silty fines, and 16% fine sub-rounded gravel size. the maximum size is 20 mm. the liquid limit is 33% and the plastic limit is 27%. d) this soil has 74% fine to coarse sub-angular reddish sand and 26% organic and silty dark brown fines. the liquid limit is 37% when not dried and is 26% when oven dried. the plastic index is 6% when not dried.

Which notation is used to represent an alpha particle? a. b. c. d.

Pl asaaap ! match the term to the correct description. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. movement that is like a t transfers energy from one location to another 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave