MKS (METRIC) SYSTEM OF UNITS EXPLAINED - CONVERSIONS CALCULATOR
Confused in the conversion jungle?
Units in the MKS-system (metric, or SI system) are based on the Laws of Newton.
MKS stands for: Meter-Kilogram-Second.   Length in meter, mass in kg, time in seconds
Force = mass(m) x acceleration(a), F = m.a , thus kg  x  m/s2, which is the Newton (N)
weight is an inertial force, not mass! On Earth 1 kg of mass weighs 1 x 9.8 = 9.8 N		 mass and weight are the same in SAE !
Energy = Work = Force x travelled way, thus Newton x meter, the Newtonmeter (Nm), which also is called the Joule (J)  x 1000 is the kJ  (kNm) ,  the same unit for all forms of energy.
Power = energy per unit of time, thus Nm/s = J/s, also called the Watt.   x 1000 = kW = kJ/s

With this, all other units are given. There are no conversions between units, but decimal ones!
Pressure = Tensile Strength = Force/Area, in N/m2 , called the Pascal (Pa)  x 1000 = kPa  100 kPa = 14.5 psi = 1 bar.
Volume: 1 m3 = 1000 liter =  35.3 ft3  = 264.2 US gallon. 1 liter = 61 in3  
Volume flow:  1 m3/s = 1000 liter/s =  60,000 liter/min = 2119 cfm = 15,850 US gallon/min
Density: 1000 kg/m3 = 62,43 lb/ft 3 = 0.036 lb/in3
Note: Earth gravity acceleration is 32.144 ft/s2  (= 9.8 m/s2) and thus the weight of 1 pound of mass, called the pound-force (lbf), would be 32.144 lb.ft/s2  = 4.448 N (kg.m/s2). Then 1 lb.ft/s2  = 0.1394 N, which thus should be 1 lbf, but in common conversion tables 1 lbf  = 4.448 N. In SAE, weight and mass are given the same numerical value and dimension, though they are two totally different things. Therefore I have not taken up a conversion row for force (weight) - it's confusing!
Now, what is your body's weight and mass on the Moon? ( gravity acceleration g = 1.62 m/s2 )  compare with SAE .....

( including conversions below )
Temperature: 1°C = 5/9 °F and   0 °C = 32 °F, hence:  °C = (°F -32) x 5/9   Absolute temp: 0 °K (Kelvin)  =  -273.15 °C
SAE - MKS (metric) CONVERSIONS CALCULATOR
Enter a value in any box and click anywhere outside it to convert (a reset buttom clears all rows).
Volume  notation: V = l3 (length x length x length) SI-unit: cubic meter ( m3 = 1000 liter)
Gallon (US) Gallon (UK) Liter
in3
 ft3
yd3
 Fl. oz.

Length   notation: l, SI-unit: meter (m), basic unit, multiple units: km, dm, cm, mm, µm
Miles (land) Yards
 Feet
 Inches
 Fathoms
 Kilometers
 Meters
Area   notation A = l2 (length x length) SI-unit: square meter (m2)  multiple units: km2, dm2, cm2, mm2
Acres
 Hectares
 Sq Meters
  Sq inches
Sq Feet
 Sq Yards
Sq miles
Time notation: t SI-unit: second (s) basic unit,  multiple units: ms  µs, ns
Years Weeks
 Days
 Hours
 Minutes
 Seconds
Mass  notation: m   SI-unit: kilogram (kg), basic unit,  multiple units: g, mg,  µg 
additonal unit: ton (t) = 1000 kg = 1 Mg
Kilograms Pounds
 oz (ounce)
 Grains
 Sh cwt
Sh ton
 
Volume Flow  notation: qv = V/t (m3/s) SI-unit: cubic meter per second
multipile units: l/s, ml/s, (volume/ time)   1 m3/s = 3600 m3/h
Gallon/h (US) Gallon/h (UK) in3/s
 cfm - ft3/min
Liter/s
 Liter/min
 m3/h

Temperature  notation absolute temp: T.  SI-unit: kelvin (K), Celsius temp: t  unit: degree Celsius (°C)
Fahrenheit °F Celsius °C Kelvin K Rankine R Rakine is absolute temp in °F (as unit)
Kelvin is absolute temp in °C   (as unit)
thus 0 R  =  0 K
Energy   notations: W for work, E for electric, Q for heat, L for latent energy, U for internal energy)
SI-unit: Joule (J), multiple units: mJ, kJ, MJ, GJ, TJ.    1 kJ = 1000 J
kJ
 kWh
 kcal
 ft •lbf
Btu

The Joule is the general unit for all kinds of energy:
J = Nm = Ws

Power   notation: P = W/t (energy/time),  SI-unit: watt (W), multiple units:  kW, MW, GW, TW, mW,  µW
kiloWatt (kW) kcal /h hp
 ft •lbf/s

Btu/h

The Watt is the general unit for all kinds of  power:
1 W =1 J/s = 1 Nm/s

Calculation Example

An object with a mass of   m = 10 kg is accelerated by a force of  F = 100 N , during  t  = 2 minutes  = 120 seconds.
Acceleration:  a = F / m = 100 / 10 = 10 m/s2.  Traveled way S = 0.5 x a x t2 = 0.5 x 10 x 1202 = 72,000 meter = 72 km.
The object's kinetic energy: Wk = F x S = 100 x 72,000 = 7,200,000 Nm = 7200 kNm = 7200 kJ.
The object's end speed  V = a  x   t  = 10 x 120  = 1200 m/s  = 1.2 km/s = 1.2 x 3600 = 4320 km/h.
The power of the driving source (say a rocket engine) P = Wk / t = 7200 / 120 = 60 kJ/s = 60 kW (like a car's engine).

If the same energy  Wk was used to launch the object straight up (not same force, time and acceleration as above), then
Wk = Wp (potential energy) = m x g x h , where g is Earth's gravity acceleration of 9.8 m/s2 and h the height reached.
Thus  h = Wp / (m x g) = 7,200,000 / (10 x 9.8) = 73,469 meters, say 73.5 km, where it will come to a halt and start falling down again. It will hit the ground (air resistance neglected) with the energy:  Wk = 0.5 x m x V2 and thus at a speed of:
V = sqrt(2Wk / m) = sqrt ( 2 x 7,200,000 / 10) = 1200 m/s.

If it needs say 1 second to come to a halt ( forming an impact crater),  the force of the impact  F = m x a and a = V / t , thus F = m x V / t  (m x V is the impulse) = 10 x 1200 /1 =  12000 N. If we round g = 10 m/s2, the impact force is equal to the weight of a mass of 1200 kg (1.2 metric ton). If the contact area A of the impact was say 10 cm2  =  10 / (100 x 100) = 0.001 m2 ,   then the contact pressure would be F / A = 12000 / 0.001 = 12 x 106 = 12 MPa = 12000 kPa = 120 bar  (1 bar = 100 kPa), or 120 times atmospheric pressure.  The power of the impact is then: P = Wk / t: = 7200 / 1  = 7200 kJ/s =  7200 kW  =  7.2 MW  (see the difference between power and energy?).

Say the material of the object has a specific heat capacitivity of  a = 2 kJ/kg.°C. All its kinetic energy is converted to heat at impact and the object's temperature increases then with: DT = Wk / ( a  x  m) = 7200 / (2 x 10)  = 360 °C
Now, compare doing (not just convert the above values) this same calculation in Imperial units .....

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