Answer:
The time it takes for 14C to radioactively decay is described by its half-life. C has a half-life of 5,730 years. In other words, after 5,730 years, only half of the original amount of 14C remains in a sample of organic material. After an additional 5,730 years–or 11,460 years total–only a quarter of the 14C remains.
Explanation:
Hope this helps
i think photons with shorter wavelengths have larger speed.
I apologise if its incorrect.
Potential Energy = mgh,
where m = mass in kg, g ≈ 10 m/s², h = height above ground = 8 m
PE = mgh
= 70*10*8 = 5600 J