Agricultural Mechanization and Farm Structures Review

Comprehensive fill-in-the-blank practice flashcards for AGR208 covering technical drawing types, psychrometrics, greenhouse heating and cooling, structural load calculations, lumber specifications, fasteners, and roofing materials.

The course AGR208 Intro to Ag Mechanization is taught by instructor __________.

Dyke Barkley

__________ drawings are single-view pictorial drawings that attempt to show accurately how an object looks by depicting distant objects of the same size as smaller.

Perspective

In an __________ drawing, the object is turned so two sides and a roof are visible, edges are drawn at a $30^\circ$ angle to the horizon, and vertical lines remain vertical.

isometric

An __________ drawing features one vertical axis, one horizontal axis, and one axis at a $30^\circ$ angle to the horizontal.

oblique

In working drawings, extension lines use a $\frac{1}{16}''$ spacing, and dimension lines express measurements in inches up to __________ inches, after which measurements are expressed in feet.

24

Heat is defined as the quality of being hot and energy produced by the accelerated vibration of __________.

molecules

A Psychrometric Chart is a graph representing the __________ physical properties of air.

7

__________ temperature is the temperature of air measured with a thermometer in Fahrenheit and represents the most simple and common measuring method.

Dry-bulb

The temperature at which moisture in the air begins to condense in the form of droplets is defined as the __________.

dew point

Specific volume is defined as the volume of space occupied by one pound of dry air at __________ atmospheric pressure.

standard

A calorie is defined as the amount of heat required to raise 1 gram of water by $1^\circ\text{C}$, specifically from $14.5^\circ\text{C}$ to __________.

$$15.5^\circ\text{C}$$

One British thermal unit (Btu) equals __________ calories, and 1 horsepower equals __________ Btu.

252; 33,475

The majority of heat loss in greenhouses occurs through __________, primarily through glazing.

conduction

Heat loss through cracks around glass panels, doors, and fans occurs via mass airflow and is classified as infiltration/exfiltration (__________), accounting for up to 10% of total heat loss.

convection

While glass, vinyl plastic, and water do not readily allow radiant energy to pass, metal and __________ film readily allow passage.

polyethylene

Combustion of propane in unit heaters produces water and carbon dioxide, but also releases __________, which is injurious to plants.

ethylene

Horizontal air flow (HAF) systems use small fans sized from $\frac{1}{30}$ to $\frac{1}{15}\,\text{hp}$ spaced an average of 1 fan per __________ feet of greenhouse length.

50

The formula for heat flow rate ($Q$) in Btu per hour is $Q = \mathbf{\_\_\_\_\_\_\_\_\_\_}$.

$$\frac{A \times (T_1 - T_2)}{R}$$

A material's thermal conductivity is measured by its U-value, whereas its thermal resistance is represented by its R-value, which is the __________ of the U-value.

inverse

In the United States, wind velocity pressure in pounds per square foot ($Q$) is calculated using the formula $Q = \mathbf{\_\_\_\_\_\_\_\_\_\_}$.

$$0.00256 \times V^2$$

Roof pitch is defined as the vertical rise of the roof divided by the __________ of the building, expressed as a fraction.

span

In Illinois, a roof with a slope less than $20^\circ$ is designed to withstand a snow load of __________ pounds per square foot.

20

The three types of stresses caused by loads on structural members are tensile, compressive, and __________.

shear

For a uniformly distributed load on a simple beam, the maximum bending moment formula is $M = \mathbf{\_\_\_\_\_\_\_\_\_\_}$.

$$\frac{1}{8} \times W \times L$$

A nominal $2'' \times 4''$ wood stud actually measures __________ inches by __________ inches.

1.5; 3.5

Logs are processed into four types of lumber: dimension lumber, common boards, finish lumber, and __________ lumber.

pattern

The formula to calculate board feet of lumber is $\text{Board Feet} = \mathbf{\_\_\_\_\_\_\_\_\_\_}$, where $T$ and $W$ are in inches and $L$ is in feet.

$$\frac{T \times W \times L \times N}{12}$$

Estimations require 20 lbs of nails per 1,000 board feet of common boards and __________ lbs of nails per square of roofing.

5

To satisfy allowable lateral load conditions for nails driven into side grain, the depth of penetration must be at least $\frac{2}{3}$ the nail length for softwood and __________ the nail length for hardwood.

$$\frac{1}{2}$$

Metal straps can increase joint strength by about 25%, while __________ timber connectors are used where very high loads must be transmitted between wood members.

split-ring

Asphalt shingles recommended for farm structures weigh __________ lbs per square and require roofs with a minimum rise of 4 inches per foot of run.

235

Galvanized sheet roofing stored wet forms __________ zinc carbonate, which accelerates metal corrosion.

white

In the roof diagram shown, the ratio of vertical rise to horizontal run defines the __________ of the roof slope.

slope angle

In the provided lumber defect diagram, the defect labeled at the top with separations extending through the wood is called __________.

splits

According to the Green Roof Design diagram, the layer located directly above the roofing membrane and structural support is the __________.

Membrane Protection and Root Barrier