# hw22 - PHYS-1200 PHYSICS II HOMEWORK SOLUTIONS CLASS 22...

This preview shows pages 1–2. Sign up to view the full content.

PHYS-1200 PHYSICS II SPRING 2005 HOMEWORK SOLUTIONS CLASS 22. 38.10, 38.19, 38.28, 38.68; Q38.09, Q38.13 38.10. a) The rate of solar energy (or solar power) that strikes the panel is, P = IA = (1.39 kW/m²)(2.60 m²) P = 3.61 kW b) The rate at which solar photons are absorbed by the panel is, m/s) 10 s)(3.0 J 10 (6.63 m) 10 W)(550 10 61 . 3 ( 8 34 9 3 × × × × = = = = - - hc P hf P E P R photon λ R = 9.98 ×10 21 s -1 c) Avogadro’s number is the number of photons in one mole, so the time to collect one mole of photons is, 1 - 21 23 s 10 98 . 9 10 02 . 6 × × = = R N t A t = 60.3 s 38.19. a) K max = hf φ = eV 20 . 4 m 10 00 2 m/s) 10 s)(3.0 eV 10 (4.14 9 8 15 - × × × = - - - hc K max = 2.01 eV b) The least energetic electron that escapes has just enough energy to get out, so it has no kinetic energy. K min = 0 c) The stopping potential is given by, eV = K max . So, C 10 1.6 J/eV) 10 eV)(1.6 01 . 2 ( 19 19 max - - × × = = e K V V = 2.01 V d) The cutoff wavelength is given by, =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 09/17/2008 for the course PHYS 1200 taught by Professor Stoler during the Spring '06 term at Rensselaer Polytechnic Institute.

### Page1 / 2

hw22 - PHYS-1200 PHYSICS II HOMEWORK SOLUTIONS CLASS 22...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online