Sem 2 Final Review 2015 KEY 34-66lehmanlchs.weebly.com/uploads/2/6/3/0/26305186/sem_2...PF Sem 2 Final Review Guide Name: __Answer Key_____ 34. Draw a graph representing the relationship

PF Sem 2 Final Review Guide Name: __Answer Key_____

34. Draw a graph representing the relationship between the current of an electromagnet and the electric field created by it. 35. What type of current is produced by electromagnetic induction? How do you know? 36. An electric motor converts: 37. Which of the pictures produces the most current? 38. How does a ripcord generator produce electricity? 39. What type of current is produced? AC or DC? 40. To increase the amount of current Produced on the ripcord generator, will it need to go faster or slower?

34. 35. 36. 37. A B C 38. 39. 40.

AC##because#the#current#changes#

direction#as#the#magnetic#field#changes.#

Electrical#energy#into#mechanical#energy#

C#

More#

coils!#

As#the#magnets#rotate#near#a#coil#of#

wire#the#changing#magnetic#field#

induces#an#electric#current#to#flow#

through#the#wires.#

AC#

It#needs#to#spin#faster#

Current!

Mag.#Field!

PF Sem 2 Final Review Guide Name: __Answer Key_____

41. The generator converts ____________ energy into electrical energy. HARMONIC MOTION Define the following terms: 42. Period 43. Cycle 44. Frequency 45. What is the difference between the units “seconds” and “Hertz”? 46. On a pendulum, how does increasing the mass of the “bob” effect the time of the period? 47. On a pendulum, how does changing the amplitude effect the time of the period? 48. On a pendulum, how does changing the length of the string effect the time of the period?

49. What is the only variable that changes the period of the pendulum?

50. How many cycles are represented by the distance from A to D:

51. How many wavelengths are in the graph?

41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51.

Mechanical#

The#time#it#takes#to#complete#one#cycle.#

One#complete#repetitive#motion.#

The#amount#of#waves#that#pass#each#second.#

Seconds#is#the#unit#for#the#time#of#a#period#

and#Hertz#is#the#unit#for#Frequency.#

No#effect,#since#gravity#is#the#force#that#

makes#it#swing,#heavier#things##don’t#fall#

faster.#

No#effect,#falling#farther#means#it#falls#faster#

and#shorter#is#slower.#

The$shorter$the$string#the#shorter$the$period,#longer#the#string,#longer#the#period.#

The!length!of!the!pendulum!!

1.5#cycles#(one#cycle#is#from#A#to#C)#

2#complete#waves#

PF Sem 2 Final Review Guide Name: __Answer Key_____

52. Use the graph to determine the length of string on a pendulum with a period of 1.5s

53. How many wavelengths are in the standing wave pictured above?

54. What is the wavelength of the wave pictured above?

55. What type of wave is the picture demonstrating? 56. What type of wave is a sound wave? 57. In what type of material does sound travel the fastest?

52. 53. 54. 55. 56. 57.

4!m!

30#cm#

2#waves#

2#meter#

Transverse#Wave#

Longitudinal#(Compression)#Wave#

Solids!#

Sound#doesn’t#travel#in#a#vacuum#

(no#medium)#

PF Sem 2 Final Review Guide Name: __Answer Key_____

Use the picture below to answer questions 59-62. 58. …longest wavelength? 59. …largest amplitude? 60. …highest frequency? 61. …fundamental? 62. Complete the drawing to the right. What would happen when the waves pass? 63. What type of wave interference is this? 64. Complete the drawing to the right. What would happen when the waves pass? 65. What type of wave interference is this?

66. Two dogs bark when they spot a mouse behind the couch. The Chihuahua has a high pitched bark and the Mastiff has a very low pitch. Whose scream will be heard first? Why?

58. 59. 60. 61. 62. 63. 64. 65. 66.

A! B! C! D! E! F! G!

A#

A#

G#

A#

Constructive#interference#

Destructive#interference#

Both#barks#will#be#heard#at#the#

same#time.#

They$are$traveling$through$the$same$medium$–$AIR!#

UHigh#pitch#(frequency)#has#short#

wavelength#

ULow#pitch#(low#frequency)#has#long#

wavelength#

UThus,#speed$of$waves$are$the$same$

B#A#

A#

B#