Introduction - Mathematics and Statistics for the Environment - page 11

TABLE 1.3 (continued)
Conversion Factors by Unit Category

Factor Metric (SI) or English Conversions

Units of Work or Energy

1 BTU (British Thermal Unit) 252 cal (calories)

1055.06 j (joules)
10.41 L atm (liter-atmospheres)
0.293 Wh (watt-hours)

1 cal (calories)

3.97 × 10 -3 BTUs (British Thermal Units)
4.18 j (joules)
0.0413 L atm (liter-atmospheres)
1.163 × 10 -3 Wh (watt-hours)

1 eV (electron volt)

1.602 × 10 -12 ergs
1.602 × 10 -19 j (joules)

1 erg 1 dyne-centimeter

1 × 10 -7 j (joules)
2.78 × 10 -11 Wh (watt-hours)

1 j (joule)

9.48 × 10 -4 BTUs (British Thermal Units)
0.239 cal (calories)
10,000,000 ergs = 1 × 10 7 ergs
9.87 × 10 -3 L atm (liter-atmospheres)
1.00 N-m (newton-meters)

1 kcal (kilocalorie) 3.97 BTUs (British Thermal Units)

1000 cal (calories)
4,186.8 j (joules)

1 kWh (kilowatt-hour) 3412.14 BTU (British Thermal Units)

3.6 × 10 6 j (joules)
859.8 kcal (kilocalories)

1 N-m (newton-meter) 1.00 j (joules)

2.78 × 10 -4 Wh (watt-hours)

1 Wh (watt-hour) 3.412 BTUs (British Thermal Units)

859.8 cal (calories)
3,600 j (joules)
35.53 L atm (liter-atmospheres)
Units of Power

1 hp (horsepower) 745.7 j/sec (joules/sec)

1 kW (kilowatt) 56.87 BTU/min (British Thermal Units/minute)

1.341 hp (horsepower)
1000 j/sec (joules/sec)

1 W (watt) 3.41 BTU/hr (British Thermal Units/hour)

1.341 × 10 -3 hp (horsepower)
1.00 j/sec (joules/second)
Units of Pressure

1 atm (atmosphere) 1.013 bars

10.133 N/cm 2 (newtons/square centimeters)
33.90 ft of H 2 O (feet of water)
101.325 kPa (kilopascals)
14.70 psia (pounds per square inch absolute)
760 torr
760 mmHg (millimeters of mercury)

(continues)