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| "You cany change the laws of Physics (Jim)" |
Conservation laws
A law which states that, in a closed system, the total quantity of something will not
increase or decrease, but remain exactly the same; that is, its rate of change is zero.
For physical quantities, it states that something can neither be created nor destroyed. Some
specific examples of conservation laws are:
- conservation of mass-energy
- The total mass-energy of a closed system remains constant.
- conservation of electric charge
- The total electric charge of a closed system remains constant.
- conservation of linear momentum
- The total linear momentum of a closed system remains constant.
- conservation of angular momentum
- The total angular momentum of a closed system remains constant.
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- Magnus effect
- A rotating cylinder in a moving fluid drags some of the fluid around with it, in its
direction of rotation. This increases the speed in that region, and thus the pressure is
lower. Consequently, there is a net force on the cylinder in that direction, perpendicular
to the flow of the fluid. This is called the Magnus effect.
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- Newton's first law of motion
- A body continues in its state of constant velocity (which may be zero) unless it is
acted upon by an external force.
- Newton's second law of motion
- For an unbalanced force acting on a body, the acceleration produced is proportional to
the force impressed; the constant of proportionality is the inertial mass of the body.
- Newton's third law of motion
- In a system where no external forces are present, every action force is always opposed
by an equal and opposite reaction force.
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- First law of thermodynamics
- The change in internal energy of a system is the sum of the heat transferred to or from
the system and the work done on or by the system.
- Second law of thermodynamics
- The entropy -- a measure of the unavailability of a system's energy to do useful work --
of a closed system tends to increase with time.
- Third law of thermodynamics
- For changes involving only perfect crystalline solids at absolute zero, the change of
the total entropy is zero.
- Zeroth law of thermodynamics
- If two bodies are each in thermal equilibrium with a third body, then all three bodies
are in thermal equilibrium with each other.
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