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Garrulo
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How are G, ħ & c measured??
The gravitational constant G is typically measured using a torsion balance experiment, where the torque exerted by a mass on a suspended arm is measured and compared to the gravitational force between two masses. This experiment requires precise measurements of the masses and distances involved.
The Planck constant, denoted by ħ (h-bar), is a fundamental constant in quantum mechanics that relates a particle's energy to its frequency. It is also used to calculate the uncertainty in position and momentum of a particle. It has a value of approximately 6.626 x 10^-34 joule seconds.
The speed of light is typically measured using the time-of-flight method, where the time it takes for light to travel a known distance is measured. This can be done using high-precision instruments such as lasers and mirrors. The speed of light is a constant, with a value of 299,792,458 meters per second in a vacuum.
G is measured in Newtons times meters squared per kilogram squared (N*m^2/kg^2). ħ is measured in joule seconds (J*s). c is measured in meters per second (m/s).
G, ħ, and c are all fundamental constants in physics and are related through various equations, such as the Planck-Einstein relation (E = ħω) and the Einstein field equations (G = (8πG/c^4)T). They also play important roles in theories such as general relativity and quantum mechanics.