# Factor physics question

1. Oct 10, 2005

### asdf1

for the following question:
show that the thickness x of an absorber required to reduce the intensity of radiation by a factor of 2 is given by x=0.693/(miu)

my problem:
what is meant by "a factor of 2"?

2. Oct 10, 2005

### Tide

It means that the energy is reduced to one half its starting value. BTW - 0.693 looks suspiciously close to $\ln 2$. ;)

3. Oct 10, 2005

### asdf1

thanks!!! :)
so usually, factor=mutiple?