00:01
Okay, in this question we have to calculate the fraction of the energy intercepted by the area of the body at a distance from the source.
00:09
Right.
00:10
So of the given energy emitted, only a fraction passes through the worker.
00:15
Okay? so of the given energy emitted, only a fraction passes through the worker as given in the question.
00:47
So, the total gamma ray energy decay is, total gamma ray decay will be 1 .33 plus 1 .17 as given electron volts, mega electrons volts is the unit.
01:27
This will come out to be 2 .50 mega electron volt.
01:37
Right so the total energy that is emitted by the source per second will be i will write the total energy emitted by the source per second is 0 .040 i into 3 .7 into 10 to the power 10 decays per cis second into the total gamma rate energy decay that is 2 .50 the unit also mega electron volt okay so this comes out to be 3 .7 into 10 to the power 9 mega electron volt per second next the portion of this energy intercepted by the body we will write the portion of this energy emitted by the body is its 1 .5 meter square area divided by the area of a sphere by the area of sphere of the area of sphere of radius 0 .4 .0 meters.
03:51
Okay.
03:52
Area 1 .5.
03:53
This is of the area of the body and the area of this sphere is 4.
03:58
So we will divide 1 .5 and the area of the sphere will be 4 pi r square.
04:06
Okay...