Extensional stress. is your answer.
Sodium (Na) is a Alkali metal so that's the answer
Explanation:
Given:
v₀ = 0 m/s
v = 49 m/s
a = 9.8 m/s²
Find: t
v = at + v₀
49 m/s = (9.8 m/s²) t + 0 m/s
t = 5 s
Speed of light
According to Einstein, the speed of light is constant in all points of reference. In addition, he pointed out the speed of light is the maximum speed known since in practice one can never catch up with the beam of light. This is explained by his theory of relativity.