1.3 Unit Conversions

Unit prefixes

Engineering problems often span a wide range of magnitudes, requiring prefixes to simplify representation. For example, a steel cable's weight may be in kilonewtons (kN), while the stress might be measured in megapascals (MPa).

Prefix Symbol Factor Scientific Notation
Kilo k 1,000 103
Mega M 1,000,000 106
Giga G 1,000,000,000 109
Micro µ 0.000001 10-6
Milli m 0.001 10-3
Nano n 0.000000001 10-9


Common Conversion Table

Statics often involves forces, moments, lengths, and stresses. This table focuses on conversions commonly used in statics problems.

Quantity Conversion
Time 1 hr = 60 min
Time 1 min = 60 s
Length 1 in = 25.4 mm
Length 1 ft = 12 in
Length 1 m = 1.09361 yd
Mass 1 slug = 14.5939 kg
Force 1 lb = 4.4482 N




Unit Conversion Examples

Example 1: Convert a speed of 60 mph to km/s. 1 mile = 1.60934 km.

Example 2: Convert a volume of 2 m³ to yard³.

Example 4: Calculate pressure in psi for a stress of 500 MPa.

Example 5: Determine the moment in lb-ft given a torque of 100 N-m.

Click to show the answer