EXPLANATION
GS11. What is the speed of light in a vacuum?
a) 300,000 km/s
b) 150,000 km/s
c) 3,000 km/s
d) 30 km/s
ANSWER: a) 300,000 km/s
EXPLANATION:
The speed of light in a vacuum is a) 300,000 km/s.
It is the fastest speed at which information can travel through space. It is also the speed at which all massless particles, such as photons, travel. The speed of light in a vacuum is constant, regardless of the motion of the source or observer.
