What is c give a numerical value for it as well as a definition?

Answer:

In physics, "C" is the speed of light (in a vacuum), and is equal to exactly 299,792,458 m/sec ( 1,079,252,848.8 km/hr ), or roughly 186, 000 miles/sec (671 million miles per hour).

First answer by Dfoofnik. Last edit by Dfoofnik. Contributor trust: 2561 [recommend contributor recommended]. Question popularity: 1 [recommend question].