A laser produces a beam of 4000-nm light. A shutter allows a ...

[Marty]

A laser produces a beam of 4000-nm light. A shutter allows a pulse of light, 30 ps in duration, to pass.
 
  Which of the following is closest to the uncertainty in the energy of a photon in the pulse? ( h = 1.055  10-34 J  s = 6.59  10-16 eV  s)
  A) 10-3 eV B) 10-6 eV C) 10-4 eV D) 10-2 eV E) 10-5 eV

Question 2

A 25-kg wooden sign 3.0-m long by 2.2-m high is supported by two nails along its left edge, one at the bottom of the sign and the other at the top. The nails are on the same vertical line.
 
  Find the horizontal component of the force exerted by the upper nail. A)
 
  250 N
 
  B)
 
  120 N
 
  C)
 
  360 N
 
  D)
 
  170 N
 
  E)
 
  280 N

[Heffejeff]

Answer to Question 1

E

Answer to Question 2

D

[Marty]

Both answers were spot on, thank you once again

[Heffejeff]

Great! Please up vote