Kahoot questions for Exam 2 preparation


Answers will appear at the bottom.  Thanks for playing today.

1.       What is the difference between mechanical waves and EM waves?
Mechanical waves require a medium
Mechanical waves travel at the speed of light
EM waves travel at the speed of sound
EM waves cannot travel through a medium

2.       What is the frequency of a note that is one octave above 50 Hz?
51, 75, 200, 100

3.       Which is faster, the speed of light or the speed of sound?
Speed of sound
Depends on the type of light
Speed of light
They are equal

4.       WTMD is found at 89.7 on the FM dial. What does this number represent?
Speed
Frequency
Wavelength
It has no meaning

5.       To find the frequency of the immediately adjacent key on the piano, multiply the frequency by:
2, 4, 1, 1.059

6.       What does this image represent?  (Flashlight hitting mirror)
Refraction
Reflection
Diffraction
Polarization

7.       Which region is more optically dense?  (light ray entering from above into a blue region; light ray bends toward normal line)
Blue area below
White area above
They are both the same
There is not enough information to tell

8.       When light goes from air to glass, it:
Stays the same speed
Speeds up
Slows down
Stops

9.       If the lens shown is glass, are the light rays following a possible path?  (Concave lens is depicted with rays diverging outward.)
Yes
No
Depends on the type of glass

10.   In this Doppler effect image, where would an observer measure the greatest frequency?  (Concentric circles, bunched up on the right)
On the right
On the left
Where the sound is being emitted
It’s the same everywhere

11.   To calculate the wavelength of a 440 Hz sound wave traveling at 340 m/s, calculate:
340 x 440
340 / 440
440 / 340
340 + 440

12.   On a moving airplane wing, where the air pressure greatest?
Above the wing
Below the wing
Inside the wing
It is the same everywhere

13.   What does this symbol represent? (The symbol is lambda.) 
Speed
Frequency
Wavelength
Amplitude

14.   What is the correct unit for frequency?
Meters
Seconds
Meters per second
hertz

15.   Distant galaxies are red shifted. This means:
They are rotating
Moving away from us
Moving toward us
Not moving

16.   The focal point is where:
Light rays always meet
Light rays never meet
Light rays meet if they were initially parallel
Light rays stop

17.   Light rays through a curved mirror or lens:
Always meet at the same point
Meet at different points, depending on where the object is
Never cross

18.   Moving from radio waves to gamma rays along the EM spectrum:
Frequency increases
Wavelength decreases
Speed (in a vacuum) stays the same
All of these are true

19.   Which path is possible? 
4 pictures were shown – only 1 was possible.  Remember how refraction works.

20.   Why do prisms break up light into colors?
This is not true – it is a myth
Because each color in white light refracts differently
Because glass is less dense than air
Because different colors have different speeds in a vacuum


ANSWERS


Kahoot questions for Exam 2 preparation.  Sorry about the poor (quickly done) formatting.

1.      
Mechanical waves require a medium


2.       100

3.       
Speed of light

 
4.     
Frequency


5.       1.059

6.       
Reflection


7.     
Blue area below


8.       
Slows down

9.  
Yes

10.  
On the right


11.
340 / 440


12.  
Below the wing


13.   
Wavelength


14.   
hertz

15.   
Moving away from us


16.   
Light rays meet if they were initially parallel

17.  
Meet at different points, depending on where the object is

18.   
All of these are true

19.   

20.  
Because each color in white light refracts differently



 




Comments

Post a Comment

Popular posts from this blog

Kahoot questions from this evening - answers are below

1.   1.  Which particle is fundamental (unable to be broken up further)? Proton Electron Neutron All are fundamental 2.   2.  When statically charging an object, you are actually moving: Proton Neutron Electron Quark 3.   3.  What is the voltage of a standard D-cell battery? 1 V 2 V 9 V 1.5 V 4.   4.  Two light bulbs are in series. One is unscrewed. What happens to the other one? It also goes It gets brighther Nothing happens It blinks on and off 5.   5.  What is true about the Earth's magnetic North Pole? It is the same as the Earth’s geographic North pole. It is at the equator. It is actually a south pole. None of these are true. 6.   6.  This symbol, a plain rectangle, is the electrical representation of a: Resistor Wire Battery Capacitor 7.   7.  Two light bulbs are in parallel. If the top bulb is unscrewed, what happens to...
Read more

How things wave

Image
How things wave Introduction to WAVES. So - Waves.....   We spoke about energy.  Energy can, as it turns out, travel in waves.  In fact, you can think of a wave as a traveling disturbance, capable of carrying energy with it.  For example, light "waves" can have energy - like solar energy.  Ocean waves can certainly carry energy.   There are several wave characteristics (applicable to most conventional waves) that are useful to know: amplitude  - the "height" of the wave, from equilibrium (or direction axis of travel) to maximum position above or below crest  - peak (or highest point) of a wave trough  - valley (or lowest point) of a wave wavelength (lambda - see picture 2 above)  - the length of a complete wave, measured from crest to crest or trough to trough (or distance between any two points that are in phase - see picture 2 above).  Measured in meters (or any units of length). frequency (f...
Read more

Doppler effect

Image
Doppler! The Doppler Effect First, some animation: http://www.lon-capa.org/~mmp/applist/doppler/d.htm http://falstad.com/ripple/ So above, the blue dot is emitting sound and moving to the right.  Since it is moving AND emitting sound at the same time, the waves are getting closer on the right - resulting in a shorter wavelength (or higher frequency).  And it is the complete opposite on the left. http://falstad.com/ripple/ Play with this and choose the "Doppler Effect 1" example. And for some more visuals: https://highered.mheducation.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/0072482621/78778/Doppler_Nav.swf::Doppler%20Shift%20Interactive The key in the Doppler effect is that motion makes the "detected" or "perceived" frequencies higher or lower.   It's worth noting that the effect also works in reverse. If you (the detector) move toward a sound-emitter, you'll detect a higher frequency. If you...
Read more