Since no one seems to be helping me, maybe you will help me when I post my exact work that I did. I just need someone to check them all and make sure I did the right equations and if I got the right answers or not. This is for a grade, and I desperately need a passing grade on this worksheet to even pass the class. I made an honest attempt at each.(adsbygoogle = window.adsbygoogle || []).push({});

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?

Given:

f=100.4 MHz

3x10^8

f=100.4x10^6

1004000000

-----------

3x10^8

=.335 m

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?

Given:

v=2.45x10^8 m/s

3x10^8

n=c/v

2.45 x 10^8

------------

3 x 10^8

=1.22

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

Given:

P= 750 lm

E= ?

E=P/4(pie)

E=750 lm/4(pie)

E=589.05 cd

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

Given:

E= ?

P= 1120 lm

d= 2m

E=P/4(pie)d^2

E=1120 lm/4(pie)2^2

E=22.28 lx

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.

Given:

airn=1

n=?

90 degrees

n1sinQ1=n2sinQ2

sin(9)=n2sin(nr)

2.417xsinQ2=1sin90

=24.44 degrees

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

Given:

nquartz=1.544

sin x= 1/1.544 = .647

sin-1(.647)

=40.37 degrees

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?

d= 4.6 m

cd= 78

P= 980.2

E=P/4(pie)d2

cd=P/4(pie)

CD4(pie)=P

78(4)(pie)

E=980.2/4(pie)(4.6)^2

E=3.69 lx

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# Homework Help: I really need someone to help me with these physics math problems

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