This preview shows page 1. Sign up to view the full content.
49. The fraction of undecayed nuclei remaining after time
t
is given by
N
N
ee
t
tT
0
2
12
==
−
−
λ
ln
/
/
af
where
λ
is the disintegration constant and
T
1/2
(= (ln 2)/
λ
) is the halflife. The time for
half the original
238
U nuclei to decay is 4.5
×
10
9
y.
(a) For
244
Pu at that time,
()
( )( )
9
7
1/2
ln 2 4.5 10 y
ln 2
39
8.0 10 y
t
T
×
=
=
×
and
39.0
17
0
1.2 10 .
N
e
N
−−
=≈
×
(b) For
248
Cm at that time,
ln
ln
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 05/19/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.
 Spring '08
 Any
 Physics

Click to edit the document details