Review: Special Measuring Devices, Tables, Ratios And Proportions

1. A device used to measure construction drawings. It is divided into 10, 20, 30, 40, 50, or 60 parts.

Architect's Scale

Standard Ruler

Engineer's Scale

An engineer's scale is a device used to measure construction drawings. It is divided into 10, 20, 30, 40, 50, or 60 parts. Unlike a standard ruler, which is a general measuring tool, an engineer's scale is specifically designed for accurately measuring architectural and engineering drawings. An architect's scale is also used for this purpose, but the most appropriate answer in this case is the engineer's scale.

Explanation

An engineer's scale is a device used to measure construction drawings. It is divided into 10, 20, 30, 40, 50, or 60 parts. Unlike a standard ruler, which is a general measuring tool, an engineer's scale is specifically designed for accurately measuring architectural and engineering drawings. An architect's scale is also used for this purpose, but the most appropriate answer in this case is the engineer's scale.

2. A pump has to inject 3 ounces of dye into a solution for every 3.5 gallons of that solution. If I need 17.5 gallons of solution, how many ounces of dye will need to be injected into the solution?

20 oz.

0.6 oz.

15 oz.

This proportion is directly related. The MORE solution prepared, the MORE dye that is needed.
3 oz / x = 3.5 gal / 17.5 gal; x = 15 oz.

Explanation

This proportion is directly related. The MORE solution prepared, the MORE dye that is needed.
3 oz / x = 3.5 gal / 17.5 gal; x = 15 oz.

3. Two gears are connected by a chain. A 12 inch gear with 30 teeth drives a 36 inch gear with 90 teeth. How many revolutions will the 12 inch gear complete to turn the 36 inch gear 2 revolutions?

6 revolutions

4 revolutions

2 revolutions

First, we have to determine if the ratio is inversely or directly related. The BIGGER the gear, the LESS revolutions; the SMALLER the gear, the MORE revolutions. Therefore, the proportion is INVERSELY related. 12 in / 36 in = 2 turns / x; x = 6 turns

Explanation

First, we have to determine if the ratio is inversely or directly related. The BIGGER the gear, the LESS revolutions; the SMALLER the gear, the MORE revolutions. Therefore, the proportion is INVERSELY related. 12 in / 36 in = 2 turns / x; x = 6 turns

4. Two gears are connected by a chain. A 12 inch gear with 30 teeth drives a 36 inch gear with 90 teeth. How many revolutions will the 36 inch gear need to complete to turn the 12 inch gear 10 times?

3.33 revolutions

5 revolutions

30 revolutions

This proportion is inversely related. The BIGGER gear will turn LESS revoultions. The SMALLER gear will turn MORE revolutions. 12 in / 36 in = x revolutions/ 10 revolutions.; x = 3.33 revolutions

Explanation

This proportion is inversely related. The BIGGER gear will turn LESS revoultions. The SMALLER gear will turn MORE revolutions. 12 in / 36 in = x revolutions/ 10 revolutions.; x = 3.33 revolutions

5. Tables provide comparative values of related _____________ .

Quantities

Calculations

Factors

Tables are used to present data in a structured and organized manner. They allow for easy comparison of different quantities or values that are related to each other. By looking at a table, one can quickly identify and compare the values of different quantities, making it easier to analyze and draw conclusions. Therefore, tables provide comparative values of related quantities.

Explanation

Tables are used to present data in a structured and organized manner. They allow for easy comparison of different quantities or values that are related to each other. By looking at a table, one can quickly identify and compare the values of different quantities, making it easier to analyze and draw conclusions. Therefore, tables provide comparative values of related quantities.

6. Sometimes the number of units to be converted may not be found on a table. When this happens, the answer can be calculated using addition or division

True

False

Correct answer: The answer can be calculated using addition or multiplication.

Explanation

Correct answer: The answer can be calculated using addition or multiplication.

7. A scale that is divided where inches or fractions of an inch represent feet.

Engineer's Scale

Standard Ruler

Architect's Scale

An architect's scale is a scale that is divided where inches or fractions of an inch represent feet. This scale is specifically designed for architects to accurately measure and draw scaled floor plans, elevations, and other architectural drawings. It allows them to easily convert measurements from the real world into a smaller, more manageable scale on paper. Unlike a standard ruler or engineer's scale, an architect's scale is specifically calibrated for architectural measurements and is an essential tool for architects in their design and drafting process.

Explanation

An architect's scale is a scale that is divided where inches or fractions of an inch represent feet. This scale is specifically designed for architects to accurately measure and draw scaled floor plans, elevations, and other architectural drawings. It allows them to easily convert measurements from the real world into a smaller, more manageable scale on paper. Unlike a standard ruler or engineer's scale, an architect's scale is specifically calibrated for architectural measurements and is an essential tool for architects in their design and drafting process.

8. A 10 inch diameter pulley that spins at 90 rpms is connected, by a belt, to a larger pulley. The larger pulley needs to turn at 20 rpms (revolutions per minute). What does the diameter of the larger pulley have to be in order to turn at 20 rpms?

2 inches

45 inches

36 inches

This proportion is inversely related. The BIGGER the diameter of a pulley, the SLOWER the speed. The SMALLER the diameter of a pulley, the FASTER the speed. 10 inch / x inch = 20 rpms / 90 rpms; x = 45 inches.

Explanation

This proportion is inversely related. The BIGGER the diameter of a pulley, the SLOWER the speed. The SMALLER the diameter of a pulley, the FASTER the speed. 10 inch / x inch = 20 rpms / 90 rpms; x = 45 inches.

9. What is the gear ratio between the diameters of a 54 foot diameter gear rotated by a drive motor with a 36 inch gear?

54/1

18/1

1.5/1

You have to convert 36 inches to feet. When determining gear ratios, units have to be the same.
(36 inches)(1ft/12inches) = 3 feet
Gear Ratio - driven gear/drive motor
Gear Ratio - 54 ft / 3 ft = 18/1

Explanation

You have to convert 36 inches to feet. When determining gear ratios, units have to be the same.
(36 inches)(1ft/12inches) = 3 feet
Gear Ratio - driven gear/drive motor
Gear Ratio - 54 ft / 3 ft = 18/1

10. A turbine turns at 15,000 rpms. The turbine drives a compressor at a rate of 125 cycles per second. What is the gear ratio of compressor speed to turbine speed?

2/1

1.33/1

120/1

In order to calculate the gear ratio in this problem, you must convert cycles per second to cycles per minute. The units in a gear ratio have to be the same. We can assume that cycles and revolutions are the same.
(125 cpm)(60 sec/min) = 7500 cycles per minute.
Gear Ratio - turbine speed/compressor speed
Gear Ratio - 15,000 rpm/7500 cpm = 2/1

Explanation

In order to calculate the gear ratio in this problem, you must convert cycles per second to cycles per minute. The units in a gear ratio have to be the same. We can assume that cycles and revolutions are the same.
(125 cpm)(60 sec/min) = 7500 cycles per minute.
Gear Ratio - turbine speed/compressor speed
Gear Ratio - 15,000 rpm/7500 cpm = 2/1