Units and Conversion



 

Units And Conversion

In this subject, the international system of units i.e SI system of units is used throughout to avoid any ambiguity, confusion and discrepancy. The units of some important quantities and their relations and conversion factors are dealt with in the subtopics discussed below:

Units of Length 

1 m = 100 cm = 1000 mm = 1.0936 yard

1 cm = 10 mm

1 foot = 12 inches

1 inch = 2.54 cm

1 yard = 3 feet = 36 inches = 0.9144 m

  • Sub-multiples:

  • Millimeter (mm) - 1100= 0.001 m

  • Centimeter (cm) - 1100= 0.01 m

  • Decimetre - 110= 0.1 m

  • Multiples:

  • Decameter - 10 m

  • Hectameter - 100 m

  • Kilometer (km) - 1000 m

  • Foot/Feet - ft

  • Inch - in

  • Yard - yd

Units of Area

1 Acre = 4047 square meters (m2)

= 43560 square feet (ft2)

= 4840 square yards (yd2)

= 0.4047 hectares (ha2)

1 hectare = 10000 m2 

= 2.471 acres 

= 100 ares 

1 are = 100 m2 

Acre - ac

Hectare - ha

Units of Mass and Weight 

1 kg = 1000 g = 9.81 N

1 N = 0.10197 kg

1 kN = 101.97 kg

1 g = 0.00981 N

g = gram

Kg = kilogram

N = Newton

kN = kilonewton 

Note: 1 Newton is equal to the force needed to accelerate 1 kg of mass at the rate 1m/s2
Units of Angle

1° = π/180 radians

π = 180°

2π = 360° or One complete rotation

π = 22/7 = 31415927
Units of temperature
1 cantigrade =33.8°C = 274.15°K

Centigrade - °C

Fahrenheit - °F

(1°C × 9/5) + 32 = 33.8°F

Kelvin - °K

1°C + 273.15 = 274.15°K