PHYSICS FINAL EXAM REVIEW

Answer Key!Text me if you have any questions!(Especially 1st 3rd and 6th period )

1. BFrequency is the number of

waves/vibrations/pulses/oscillations that occur in one second. Frequency is measured in Hertz.

Period is the number of seconds per wave, or 1/f

Amplitude

Wavelength

2. B, 12. A• Refraction is when the light bends as it

changes the medium it’s traveling through (air to glass, glass to water, water to air, etc)

3. A, 11. C• Refraction and Diffraction are BOTH about

waves bending, but for different reasons. Diffraction is when they spread out around the edge of a wall, or as they go through a hole in a wall:

4. D• Remember, in physics, “reflection” doesn’t

mean what you see in the mirror (that’s an image). Reflection is when waves bounce off of an object. An echo happens when sound waves reflect off of a barrier and come back to your ear.

5. B

Sound waves are the most common example of a longitudinal wave.

Longitudinal waves happen when the particles of the medium move back in forth in the same direction as the wave is moving:

6. B, 7. C• As it passes you, the apparent frequency

suddenly drops, resulting in a low pitch:

• http://www.physicsclassroom.com/Class/sound/u11l3b.cfm

8. D

• High frequency = high pitch• Low frequency = low pitch• http://plasticity.szynalski.com/tone-generator.

htm <-- This website lets you pick a frequency and will play the sound so hear the difference between a high frequency and a low frequency (only works in firefox)

• (The LOUDNESS depends on the amplitude.)

9. A

• Electromagnetic waves do not require a medium to travel through. They are transverse waves.

10. B

• Transparent = lets all light through (window)• Opaque = lets no light through (wall)• Translucent = lets some light through (frosted

window)• Luminous = gives off light (light bulb)

13. DSeries Circuits Parallel Circuits

Current is the same in all components Voltage is the same in all components

Voltage is split up between the components: VT = V1 + V2 + …

Current is split up between the components: IT = I1 + I2 + …

Total Resistance: RT = R1 + R2 + … Total Resistance: 1/RT = 1/R1 + 1/R2 + …

14. A

• Remember the electric field hockey simulation: http://phet.colorado.edu/en/simulation/electric-hockey

• To change the force on the “puck” you can change the charge of the puck OR change the size of the field.

15. A

• Ohm’s Law says I = V/R• I = Current (measured in amps)

- Current is the amount of charge flowing• V= Voltage (measured in volts)

- Voltage is the energy per charge• R = Resistance (measured in ohms Ω)

- Resistance resists or slows down the flow of charge. • According to the equation, if V increases, then so

does I. If R decreases, I increases.

16. D

• Ammeters measure amps (units of current)• Voltmeters measure volts (units of voltage)• Ohmmeters measure ohms (units of resistance)

17. C

• One path only:

18.ASeries Circuits Parallel Circuits

Current is the same in all components Voltage is the same in all components

Voltage is split up between the components: VT = V1 + V2 + …

Current is split up between the components: IT = I1 + I2 + …

Total Resistance: RT = R1 + R2 + … Total Resistance: 1/RT = 1/R1 + 1/R2 + …

RT = R+R+R+R = 4R

19. D

• Three paths:

20. B

• A circuit breaker uses an electromagnet to literally “break the circuit” if there is a dangerous level of current. (This was one of our uses of electromagnets – remember the Brainpop video we watched on electromagnets – or rewatch it. Text me for the password)

• A fuse does the same thing with a melting wire and has to replaced each time, while a circuit breaker can be reset.

21. B• Moving charges create a magnetic

field – an electromagnet. • We can increase the strength by:• -Increasing the current (usually by

increasing the voltage)• - Wrapping the wire into coils – more

coils = stronger magnetic field• - wrapping the wire around an iron

core (or any other ferromagnetic material – ferromagnetic = attracted to magnets)

22. TRUE

23. TRUE

24. TRUE

25. FALSE

26. TRUE

27. TRUE

• F = ILB

28. FALSE

29. TRUE

30. FALSE

31. FALSE

32. TRUE

33. FALSE

34. TRUE

35. FALSE

36. TRUE

37. FALSE

38. B

39. B

40. D

41. D

42. C

43. A

44. A

45. B

46. B

47. C

48. A

49. C

50. D

51. C

52. Virtual, Upright, Same Size

53. Decrease charge or Increase the distance

53 again (oops!): 3.2 X 10 -8

54. Conductor, Insulator

55. -23 microCoulombs