Question

A 3 inch fire hose has a water flow of 200 gallons per minute. What is the flow in liters per second? Note: Use US gallons not UK gallons. (10 points) The blower on an air conditioning unit produces 95 cubic feet per minute of air in the ductwork. What is the air flow in cubic meters per hour? m/hr (10 points) Torque (or moment) is the measure of turning force or twist on an object. If a mechanic is applying 12 Newton centimeters of torque on a bolt how many pound inches would this be?

Answer 1

Answer:

Case I: 12.617 L/s

Case II: 161.406 cubic meters per hour

Case III: 1.062 Pound inches

Explanation:

Given:

• Speed of water flow = 200 gallons per minute
• Speed of air blow = 95 cubic feet per minute
• Measure of Torque = 12 Newton centimeter

Assumptions:

• 1 US gallon = 3.785 L
• 1 min = 60 s
• 1 ft = 0.3048 m
• 1 h = 60 min
• 1 inch = 2.54 cm
• 1 N = 0.2248 lb

Case I:

$Speed\ of\ water\ flow = 200 \dfrac{gallon}{min}\\\Rightarrow V_{water} = 200\times \dfrac{3.785\ L}{60\ s}\\\Rightarrow V_{water} = 12.617\ L/s$

Case II:

$Speed\ of\ air\ blow = 95 \dfrac{ft^3}{min}\\\Rightarrow V_{air} = 95\times \dfrac{(0.3048\ m)^3}{\dfrac{1}{60}\ h}\\\Rightarrow V_{air} = 95\times (0.3048)^3\times 60\ m^3/h\\\Rightarrow V_{air} = 161.406\ m^3/h$

Case III:

$Measure\ of\ torque = 12\ N cm\\\Rightarrow \tau = 12\times (0.2248\ lb)\times \dfrac{1}{2.54}\ in\\ \Rightarrow \tau = 1.062\ lb in$