<p align="right">Last Update: <font color="#4f81bd">July, 13, 2024</font></p> ## BIG IDEAS - Physical qualities that are universal and have a constant value. - May be designated as a letter or symbol. ## Examples - [[Speed of Light]] - [[Planck’s constant]] - [[Hubble Constant|Hubble constant]] - [[Elementary charge|Elementary charge]] - Boltzmann constant - Avogadro constant Our first physical constant used in physics is acceleration due to gravity. It has a value of 9.8 meters per second per second. We will use the small letter g to represent the value of acceleration due to gravity. You substitute in the numeric value of 9.8 m/s2 when you see the small letter g. Note: The upper and lower case of a letter is very important in physics. There is a huge difference between the small g and the capital G. It is also very important to notice that the g for acceleration due to gravity should not be confused with the g for the unit grams. ## Sources [Meet the Constants | NIST](https://www.nist.gov/si-redefinition/meet-constants) --- Return [[Home|Home]] | [[SI units]] | [[Base Units]]