00:01
In this question, the radioactivity initially i .e.
00:05
T equal to 0 hours, this activity is equal to 8 .93 multiplied by 10 raised to the power 4 bq and after 3 .95 hours i .e.
00:20
T equal to 3 .95 hours, this activity is equal to 6 .43 multiplied by 10 raised to the power 4 bq, then we need to find this constant k in the radioactive activity.
00:36
So here we can write radioactive activity with time is given by a is equal to a naught e raised to the power minus kt.
00:52
So this k that we need to determine and this a naught is activity at t equal to 0 hour.
01:02
So here this is our a naught.
01:05
So let's put all these values here.
01:07
We will get 6 .43 multiplied by 10 raised to the power 4 equal to 8 .93 multiplied by 10 raised to the power 4 and this is multiplied by e raised to the power minus k times 3 .95.
01:24
Again we can write this as e raised to the power minus 3 .95 k equal to 6 .43 multiplied by 10 raised to the power 4 divided by 8 .93 multiplied by 10 raised to the power 4...