converting

CE 1301- Homework # 4, Unit Conversion & Estimation Exercises

1 - Convert the following values from current units used, to the new units requested & to values expressed with fundamental SI units (m kg s). As an aid, a table of unit conversion values can be downloaded from the class content section of blackboard.

Value	Value with new units of:	With fundamental SI units
100 ft hr-1	m hr-1
100 lbf	N
14.7 psi	Pa
1 atm	mm Hg
299 hectare	km2
800 hp	kW
55 mile hr-1	km s-1
400 Btu	J
3 cSt	km2 s-1
100 cP	Pa s
Example 1 gal	Example 3.785 L	Example 3.785 10-3 m3

2 - How many cubic yards of concrete is required to construct 5 miles of highway?

First, consider the following assumptions. In case of rough estimation, choose the most reasonable number which is closest to your own estimate. Show your work with unit conversions for full credit.

There are (12, 4, 16) lanes.

Each lane is (36, 12, 6) ft wide.

The road way is paved with (0.5, 20, 2) ft of material.

(12, 3, 24) ft wide shoulders on each side of the road.

3 - How many liters of water would be saved if everyone in the United States who does not turn off the faucet while they brush their teeth, did so? Assume One-third of people leave water running while bushing.

First, consider the following assumptions. In case of rough estimation, choose the most reasonable number which is closest to your own estimate. Show your work with unit conversions for full credit.

Average number of tooth brushings per person per day is (5, 10, 0, 1).

The population of the United States is (300 million, 75 billion , 75 million, 300 billion)

Average time to bush teeth is (2, 20 , 10 , 0.2) minutes.

Average faucet flow rate is ( 10, 0.2, 20, 2) gal/min.

4 - If all the land (both currently inhabitated and all the inhabitable land) were divided equally among the people now living, how many acres of land would each one have?

First, consider the following assumptions. In case of rough estimation, choose the most reasonable number which is closest to your own estimate.

The diameter of the earth is (800, 12,000, 8,000 18,000) miles.

The faction fraction of the total surface that is land is (0.1, 0.3, 0.5, 0.7, 0.9).

The number of people on earth is (700 million, 35 billion, 7 billion, 70 billion, 900 million, 100 million).