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Nader AbdlGhani
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Despite being a constant, It has both dimensions and a unit, can someone kindly explain why ?
Nader AbdlGhani said:Despite being a constant, It has both dimensions and a unit, can someone kindly explain why ?
Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physicsZapperZ said:This question is puzzling. Are you saying that the property of a "constant" includes NO dimensions and NO units?
"c", the speed of light in vacuum, is a constant. It has "dimensions and units". Why are you not asking about that as well?
Zz.
Bystander said:
Nader AbdlGhani said:Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physics
As zapperz has pointed out, you are confusing terms. The examples you site are not physical constants, they are just numbers. If used in an equation, they can be called constants as far as math is concerned, but that has nothing to do with physical constants like cNader AbdlGhani said:Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physics
Planck's constant, denoted by the symbol h, is a fundamental constant in physics that relates the energy of a photon to its frequency. It has dimensions of energy multiplied by time, and its unit is joule-second (J·s). This is because Planck's constant is used in equations that involve both energy and time, such as the Planck-Einstein relation and the Heisenberg uncertainty principle.
The dimensions of Planck's constant are significant because they reveal its role in the fundamental laws of physics. Its dimensions of energy multiplied by time show that it is involved in the measurement of energy changes over time, which is crucial in understanding the behavior of subatomic particles and the principles of quantum mechanics.
Joule-second is the most commonly used unit for Planck's constant because it is derived from the SI units of energy (joule) and time (second). This unit is also convenient because it allows for easy conversions between energy and frequency, which are both relevant quantities in many physical phenomena.
The value of Planck's constant determines the scale at which quantum effects become noticeable. It is a very small value (6.626 x 10^-34 J·s), and its presence in equations such as the Heisenberg uncertainty principle shows that at the scale of subatomic particles, energy and time are inherently uncertain and cannot be measured simultaneously with absolute precision.
No, Planck's constant cannot be measured directly as it is a fundamental constant in physics. However, its value can be determined experimentally by measuring other physical quantities such as the frequency or energy of a photon. These measurements can then be used in equations involving Planck's constant to obtain a numerical value.