physics unit and measurement

Fundamental units in the SI system

Meter (m) for length, Kilogram (kg) for mass, Second (s) for time, Ampere (A) for electric current, Kelvin (K) for thermodynamic temperature, Mole (mol) for amount of substance, Candela (cd) for luminous intensity.

Convert 15 kilometers to meters

15 km = 15,000 m.

Precision

The degree of reproducibility or agreement between repeated measurements; high precision means measurements are close to each other.

Accuracy

How close a measurement is to the true or accepted value; high accuracy means the measurement is close to the true value.

Area of a rectangular garden (10.5 m x 6.8 m)

Area = Length x Width = 71.4 m² (rounded to 71 m² for significant figures).

Convert 25°C to Kelvin

K = °C + 273.15; 25°C = 298.15 K.

Light-year

The distance light travels in one year; approximately 9.461 x 10^15 meters.

Speed conversion (20 m/s to km/h)

20 m/s = 72 km/h.

Systematic Errors

Consistent and repeatable errors that affect all measurements in the same way; example: a miscalibrated instrument.

Random Errors

Unpredictable errors that vary in magnitude and direction with each measurement; example: fluctuations in environmental conditions.