suppose that you measure a 480 count per minute (cpm) on your radiation detector placed 6 m from that radiation source , if you moved to a distance of 4m , the count rate would be ...
a)1620 cpm
b)320 cpm
c)1080 cpm
d)480 cpm
suppose that you measure a 480 count per minute (cpm) on your radiation detector placed 6 m from that radiation source , if you moved?
2017-12-31 10:21 am
回答 (2)
2017-12-31 10:47 am
✔ 最佳答案
No. of cpm is inversely proportional to the distance between the detector and the radiation source.No. of cpm ∝ (1/distance)²
When the detector is moved to a distance of 4 m, No. of cpm
= (480 cpm) × (6/4)²
= 1080 cpm
The answer: C) 1080 cpm
2017-12-31 11:50 am
Inverse square law problem
I1/I2=D2^2/D1^2
Or simplified as the previous answer.
It still comes up to 1080. The meter was moved 1/3 the distance to the source. Which will increase the rate by 1.25 times. This is a given, just as surely as cutting the distance by 1/2 will give you a dose rate four times greater.
I1/I2=D2^2/D1^2
Or simplified as the previous answer.
It still comes up to 1080. The meter was moved 1/3 the distance to the source. Which will increase the rate by 1.25 times. This is a given, just as surely as cutting the distance by 1/2 will give you a dose rate four times greater.
收錄日期: 2021-04-18 18:00:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20171231022149AAt2aR6