Biomedical Engineering Reference
In-Depth Information
Appendix A
Physical Constants
Planck's constant,
h
10
-34
Js
=
6.6261
×
10
-34
Js
=
h
/2
π
=
1.05457
×
Electron charge,
e
10
-19
C
10
-10
esu
=
-1.6022
×
=
-4.8033
×
Velocity of light in vacuum,
c
10
8
ms
-1
=
2.997925
×
Avogadro's number,
N
0
=
10
23
mole
-1
Molar volume at STP (0
◦
C, 760 torr)
=
22.414 L
Density of air at STP (0
◦
C, 760 torr)
=
1.293 kgm
-3
=
6.0221
×
10
-3
gcm
-3
1.293
×
10
7
m
-1
First Bohr orbit radius in hydrogen,
a
0
=
Rydberg constant,
R
∞
=
1.09737
×
10
-11
m
5.2918
×
Ratio proton and electron masses
=
1836.15
Electron mass,
m
= 0.00054858
AMU
=
0.51100 MeV
= 9.1094 × 10
-31
kg
Proton mass
=
1.0073 AMU
=
938.27 MeV
= 1.6726 × 10
-27
kg
H atom mass
=
1.0078 AMU
=
938.77 MeV
= 1.6735 × 10
-27
kg
Neutron mass
=
1.0087 AMU
=
939.57 MeV
= 1.6749 × 10
-27
kg
Alpha-particle mass
=
4.0015 AMU
=
3727.4 MeV
= 6.6447 × 10
-27
kg
Boltzmann's constant,
k
=
10
-23
JK
-1
1.3807
×
Principal source: E. R. Cohen and
B. N. Taylor, “The Fundamental Physical
Constants,”
Physics Today
,
56
(No. 8),
pp. BG6-BG13, August (2003). Updated and
available online at http://www.
physicstoday.org/guide/fundcon.html
The metric (SI) system of units is
summarized in Robert A. Nelson's “Guide for
Metric Practice,” available at
http://www.physicstoday.org/guide/metric.html
See also National Institute of Standards and
Technology, Physical Reference Data,
http://www.physics.nist.gov/cuu/Constants
