exam2Soln - Phys 222 Spring 2006 Exam 2, Wed 29 Mar,...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Phys 222 Spring 2006 Exam 2, Wed 29 Mar, 8-9:30pm Closed Book, Calculators allowed Turn off all cell-phones, beepers, pagers Any call will result in the end of your exam Each question is worth one point, answer all questions Fill in your Last Name, Middle initial, First Name Your ID is the middle 9 digits on your ISU card. Please fill in your recitation section in special codes K to L For the H1 section please use section 18 At end of exam, please put exam writeup back in the folder, this allows you the chance to appeal the grading Best of luck, Craig Ogilvie PLEASE START at QUESTION 25
Background image of page 1

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

View Full DocumentRight Arrow Icon
25) You are listening to a rock band concert and want to move closer to the stage. You model the sound system (single bank of speakers) as emitting sound uniformally forward (in a half- sphere) such that sound radiates equally in all forward directions. You walk towards the speakers and end up a factor of two closer than your original position. At your new position compared to your previous position a. The amplitude of the sound wave has increased by a factor of two, and the intensity has increased a factor of four b. The amplitude of the sound wave has increased by a factor of two, and the intensity has increased a factor of two c. The amplitude of the sound wave has increased by a factor of four, and the intensity has increased a factor of four d. The amplitude of the sound wave has increased by a factor of four, and the intensity has increased a factor of two Intensity ~ 1/r 2 , so intensity increases by factor of four Intensity ~amp 2 , so amplitude increases by factor of 2 26) A clarinet is 66 cm long and can be modeled as open-closed tube (the player's lips and reed "seal" the tube at one end). The speed of sound in warm air is 350 m/s. What is the frequency of the lowest note on a clarinet? a. 265 Hz b. 354 Hz c. 133 Hz d. 176 Hz e. 530 Hz Hz v f f v L 133 66 . 0 4 350 4 = × = = => = = λ
Background image of page 2
27) Two particles having the same charge, but different velocities, are moving in a uniform magnetic field (see the figure below where the velocity vectors are drawn to scale). Which particle experiences the largest magnitude magnetic force? a. Particle 1 b. Particle 2 c. Particle 1 and particle 2 experience the same magnitude magnetic force B qv B qv F F = = = ) sin( | | θ r Since v ^ (component of v perpendicular to B) is the same for both particles, F is the same 28) The fact that the magnetic force on a moving charge is perpendicular to the velocity of the charge implies that a. the moving charge cannot accelerate at all. b. no work is done by the magnetic field on the moving charge. c. the moving charge gains or loses kinetic energy. d. all of the above F is ^ to v so F is ^ to dl hence F dl = 0 and no work is done
Background image of page 3

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

View Full DocumentRight Arrow Icon
29) A charged particle of charge 1.6 x 10 -19 C and mass 1.7 x 10 -27 kg is moving at v=3 x 10 6 m/s in a uniform magnetic field of strength B=0.5T. The particle's velocity vector is transverse to the B-field so the particle undergoes circular motion. What is the radius of the circular orbit?
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/26/2008 for the course PHYS 222 taught by Professor Johnson during the Spring '07 term at Iowa State.

Page1 / 13

exam2Soln - Phys 222 Spring 2006 Exam 2, Wed 29 Mar,...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online