Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Planck length expression · CAP 2003 #19
Physics · modern-physics
Problem
The smallest length scale known in physics is the Planck length. It is an important ingredient in some current cosmological theories. Which of the following expressions could represent this Planck length? (a)
e
2
/
h
c
\sqrt{e^2/hc}
e
2
/
h
c
; (b)
h
c
/
G
\sqrt{hc/G}
h
c
/
G
; (c)
G
h
c
\sqrt{Ghc}
G
h
c
; (d)
h
G
/
c
3
\sqrt{hG/c^3}
h
G
/
c
3
.
Browse the problem library