Some math questions I need checked

  • Thread starter indiansfan4life
  • Start date
In summary: E=I/d^2 E= 78/4.6^2 = 3.6In summary, the conversation covers various problems related to light and optics, such as the wavelength of a wave, the index of refraction, luminous flux, illuminance, and angles of refraction and incidence. The answers provided are 100.4 x 10^6 for #15, 1.22 for #16, 24.44 degrees for #19, 40.37 degrees for #20, and 3.6 for #22. However, the person asking for help is unsure and has shown their attempts at solving the problems.
  • #1
indiansfan4life
16
0
analysis:
10. the picture that we see in a mirror is called the
my answer=image
11. the actual object that makes a picture that we see on a mirror is called the
my answer=specular

-problems- show your work

15. What is the wavelength of a wave with a frequency of 100.4 MHz?

16. A substance allows light to travel through it with a velocity of 2.45 x10^8 m/s. What is the substances index of refraction?

17. What is the intensity of a light that has a lumnious flux of 750 lumens?

18. What is the illuminance provided by a light with a luminous flux of 1120 lm when it is 2.3 meters away?

19. What would the angle of refraction be if a light ray starts in a diamond and goes into the air it has an angle of incidence of 9 degrees.

20. What is the critical angle of light going from quartz to air?

22. What is the illuminance of a light when it is 4.6 m away from a light with an intensity of 78 candle power?

thanks for any help I don't know what I am doing

Here's my answers:

#15: .335 m
#16: 1.22
#17: I was not sure how to do this one.
#18: I was also not sure how to do this one.
#19: 24.44 degrees
#20: 40.37 degrees
#22. 3.6
 
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  • #2
Show that you've tried. Providing the answers is not enough.
 
  • #3
#15: 100.4 x 10^6

3 x 10^8

divide c by f

=.335

#16: 2.45 x 10^8/ 3x 10^8 =1.22
#17: Like I said, I don't know what to do
#18: Dunno what to do
#19: 2.417(SIN)Q2=1(SIN)90
=24.44 degrees
#20: I just plugged it in and got 40.37 degrees for this one
SIN X= 1/1.544 then I did some other work to get the angle

#22: I wasn't really sure with this one but I used the illuminance equation to solve. I doubt it's right.
 

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