Question

Can a particle travel faster than speed of light in a medium

Answer 1

Answer:

Nothing can travel faster than the speed at which light travels *in a vacuum*. But, as explained here, it's possible to slow light down in a medium other than vacuum. In such a medium, it's possible to have a source of light that travels faster than light does *in that medium*.

Answer 2

Here you go

Explanation:

When a charged particle does move through a medium at a speed higher than the speed of light in that medium, a faint radiation is produced by the medium. In water, for example, the charged particle excites the water molecules, which then return to their normal state by emitting photons of blue light