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Meson080
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Won't the sentence be complete if its mentioned, with respect whom the particle remains at rest or moves with constant velocity?
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The below sentence has been extracted from the book-Concepts of Physics 1-H C Verma:
Newton's first law of motion: If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e, remains at rest or moves with constant velocity).
Any inertial frame will do.Meson080 said:Won't the sentence be complete if its mentioned, with respect whom the particle remains at rest or moves with constant velocity?
Meson080 said:Won't the sentence be complete if its mentioned, with respect whom the particle remains at rest or moves with constant velocity?
And if "all the forces" includes inertial-forces, non-inertial frames work too.Doc Al said:Any inertial frame will do.
Newton's first law of motion: If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e, remains at rest or moves with constant velocity) with respect to an inertial frame.
Yes, makes sense to me.Meson080 said:I hope the above statement makes sense, does it?
Photons are always moving at speed C with respect to a local frame. Newton's laws do not apply to photons. At high speeds, Newton's laws must be replaced with special relativity.Does the Newtons first law hold good for particles "photons"?
Doc Al said:Photons are always moving at speed C with respect to a local frame. Newton's laws do not apply to photons. At high speeds,Newton's laws must be replaced with special relativity.
Newton's first law is fine, even in relativity. Newton's third law has problems, even non-relativistically. (Consider electromagnetic forces.) But when generalized to conservation of momentum, it's fine.Meson080 said:I am not happy with just one letter "s" in your word Newton's law"s". It made sense to me to say that Newton's second law doesn't hold good for higher speeds, because of not considering mass to be constant. But, why doesn't Newton's first and third law hold good for higher speeds?
Newton's First Law of Motion states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
Inertia is the tendency of an object to resist changes in its state of motion. This means that an object at rest will stay at rest, and an object in motion will continue moving in the same direction and at the same speed, unless acted upon by an external force.
An example of Newton's First Law in everyday life is when you are riding in a car and the car suddenly stops. Your body will continue moving forward due to inertia until the seat belt or airbag stops you.
The more mass an object has, the more inertia it has. This means that it will require more force to change the object's state of motion. For example, a heavier object will be harder to push or stop compared to a lighter object.
A balanced force is when the net force acting on an object is zero, meaning there is no acceleration. Newton's First Law states that if an object is at rest or moving at a constant velocity, the net force acting on it must be zero. This means that the forces are balanced and the object will continue its current state of motion.