**A. Magnitude**

In the field of measurement technology is a routine activity undertaken by the technocrats to measure a wide range of systems, products and machine elements. As exemplarily: measure the diameter and length of an axis, measuring the temperature of the steam from a boiler, measure the time it takes to process a product, measures the force required to cut the material, to measure the speed of the vehicle, measure the amount of energy generated from a steam turbine or measure electric current generated by the dynamo. By the time the measurement was recorded, recorded or written to the figures, “measurements are written with the numbers called quantitative scale”.

B. **Macam Macam Magnitude**

In the measurement, the magnitude grouped into:

o The amount of scalar

o The magnitude of the vector

1. **Magnitude Scalar**

Scalar quantity which has a large magnitude or value only, example:

o Measuring length: 5 meters, 2 km.

o Measuring temperature: 40 ° C, 80 ° R

o Measure Volume: 3 liters, 4m3.

o Measure mass: 2 kg, 4 lb.

The figures only show the size or magnitude of any value. “The amount is large or has just called a scalar quantity value”.

2. **Vector Magnitude**

Vector Magnitude scale which shows that large or value and have a direction, for example:

o Measuring the speed of a vehicle, for example, 60 km / h.

o Measuring the Earth’s gravity was recorded 9.81 m / s2.

o Measuring the force of the piston which is doing business.

The magnitude of the above in addition mempiunyai magnitude value also has directions. “The amount that has magnitude and direction called Vector”.

**C. Unit**

Measuring a magnitude is measured by comparing the amount of similar magnitude is referred to as a unit, for example long measuring units meters, kilo meter. Meter and kilo meter long menunjuknan comparison. An athlete running at a speed of 2 m / sec. Two figures show the scale and meter / second is unit. A motorist saw Spedo-meter which indicates the size of 60 km / h.

Figure 60 shows the magnitude and km / h is a unit. So any scale should always be followed with the unit. SI system is the International Unit system where the SI system is a development of the system MKS. The units in the system of International Units are as follows:

o The length of the unit Meters (m)

o Mass unit Kilogram (Kg)

o Time unit Second (s)

o The temperature units degrees Kelvin (OK)

o Strong current unit Ampere (A)

o The intensity of the light unit Kandela (Cd)

o The amount of the unit mole (mol)

o Style unit Newton (N)

o Density unit kg / m 3.

o Pressure unit N / m2 or N / mm2.

o effort or work satuannyaJ = Nm

o Power unit Watt = J / s

o The speed unit m / s

o Acceleration units m / s2.

o Speed angle unit rad / s

o Accelerate corner unit rad / s2.

o The frequency unit Hertz (Hz)

**d.** **Magnitude and Units**

Magnitude and units are often used in mechanics are:

o Long

o Mass

o Time

o Style