How can a particle have energy but no mass?when there is an equation E=mc^2.
Another question how can light particles have momentum without mass !When p=mv>>>>>>>>>DOUBT PLZ CLARIFY!
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The concept of a particle having energy but no mass can be a bit confusing. In physics, there are particles called "massless particles" that indeed have energy but no mass. The most famous example is the photon, which is the particle that represents light. According to the equation E=mc^2, where E is energy, m is mass, and c is the speed of light, it might seem that a particle needs to have mass to possess energy. However, this equation is a special case that applies to rest mass, which is the mass of an object when it is at rest. The equation can be expanded to E^2=(mc^2)^2+(pc)^2, where p is momentum. For a massless particle like the photon, m=0, so the equation simplifies to E=pc, meaning that its energy is directly proportional to its momentum. Although a massless particle has no rest mass, it can still have momentum and energy due to its motion.
Now, regarding your second question about how light, which consists of photons, can have momentum without mass, let's take a closer look at the equation p=mv. This equation is the momentum formula, where p represents momentum, m represents mass, and v represents velocity. However, this equation is a classical formula that applies to macroscopic objects with mass. When it comes to particles, particularly massless particles like photons, we need to use special relativity to describe their behavior. In special relativity, the equation for momentum is p=mv/√(1-(v^2/c^2)), where c is the speed of light. For a photon, m=0, so the equation simplifies to p=mv/√(1-0), which becomes p=mv/1, and finally p=mv. However, since the mass of a photon is zero, its momentum is solely determined by its velocity. Therefore, light particles can indeed have momentum without possessing mass.
I understand that these concepts might seem counterintuitive, but they have been established through scientific experiments and theoretical frameworks. If you have any further doubts or need additional clarification, please let me know! Doubts are a crucial part of learning and understanding.