# hw05 - PHYS-1200 PHYSICS II HOMEWORK SOLUTIONS CLASS 5...

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

PHYS-1200 PHYSICS II SPRING 2005 HOMEWORK SOLUTIONS CLASS 5. 26.08, 26.32, 26.39, 26.43; Q27.02, Q27.07 26.08. a) J = n p ev p = (8.70 cm -3 )(10 6 cm 3 /m 3 )(1.60 ×10 -19 C)(470 ×10 3 m/s) J = 6.54 ×10 -7 A/m 2 b) i = JA , where A is the area that intercepts the protons. Since Earth looks like a disk from the Sun, A = π R 2 , where R is the radius of Earth. i = J R 2 = (6.54 ×10 -7 A/m 2 ) (6.37 ×10 6 m) 2 i = 8.34 ×10 7 A 26.32. J = ( ne ) v d , so ne J v d = . J 1 , the current density in section 1 is needed. Information is given to calculate J 2 , the current density in section 2. Then, since the current in section1 must equal the current in section 2, J 1 A 1 = J 2 A 2 , or J 1 ( R 1 2 ) = J 2 ( R 1 2 ), so 2 2 2 2 2 1 1 2 2 1 2 1 4 1 2 1 2 / J J J R R J R R J = = = = . To get J 2 use, m 10 69 . 1 m) 00 . 2 /( V) 10 0 . 10 ( / 8 6 2 × × = = = - - ρ L V E J = 296 A/m

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

hw05 - PHYS-1200 PHYSICS II HOMEWORK SOLUTIONS CLASS 5...

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

View Full Document
Ask a homework question - tutors are online