Answer C. The magnetic field changes direction too.
Let the Blaise runs for time "t" to complete the race
so the total distance he moved is given by

Now Issac runs for time t = "t - 2*60"
because it took rest for 2 minutes

now it is given that Blaise wins by 10 m distance




now the distance moved by Blaise is given by

Autonomic, but I don’t know why! Research this if you can.
The correct answer is B) Ultraviolet light source. Hope this helps.
Answer:
4589.05 year
Explanation:
The relation of activity is given by
we have given
Half life 
We know that half life 

So 


