Half life is 5700 years,that is 50%.
6.25% means 1/16 of the life is left.
T^1/16 =T^1/2*4.
5700 × 4 =22800 years
Nuclear physics<span> is the study of the protons and neutrons at the centre of an atom and the interactions that hold them together in a space just a few femtometres (10-15 metres) across. It would be advantageous because we understand how atoms behave. Hope this answers the question.</span>
The last one, Kinetic energy bc it is taking them to school
Answer:


Explanation:
When coefficient of friction is approximately zero then we have



here we know that

R = 30 m


now when friction coefficient is 0.30 then we have


now we have



