Nucleus a decays into the stable nucleus b with a half-life of 22.07 s. at t=0 s there are 1,293 a nuclei and no b nuclei. at what time will there be 779 b nuclei?

29.38 seconds

Explanation:

Half life, T = 22.07 s

No = 1293

Let N be the number of atoms left after time t

N = 1293 - 779 = 514

By the use of law of radioactivity

Where, λ is the decay constant

λ = 0.6931 / T = 0.6931 / 22.07 = 0.0314 decay per second

so,

take natural log on both the sides

0.9225 = 0.0314 t

t = 29.38 seconds

c because the news are a source of information of things that happen on the daily and shows evidence about that particular topic

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min