CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

The activity of a radioactive substance falls to $$87.5$$% of the initial value of $$5$$ years. What is the half-life of the element? Calculate the time in which the activity will fall by $$87.5$$%.


Solution

Case-I    $$Ao=100$$
              $$A=87.5$$
              $$t=5$$ year
              $$5=\dfrac { 2.303\times t1/2 }{ 0.693 } \times log\left( \dfrac { 100 }{ 87.5 }  \right) $$
              $$t1/2=25.9$$
                       $$=26$$ years
Case II   $$Ao=100$$
              $$A=100-87.5=12.5$$
              $$t=\dfrac { 2.303\times 26 }{ 0.693 } \times log\left( \dfrac { 100 }{ 12.5 }  \right) $$
              $$t=78.0$$ years

Physics

Suggest Corrections
thumbs-up
 
0


similar_icon
Similar questions
View More


similar_icon
People also searched for
View More



footer-image