Question

Please help...

Answer 1

@amistre64

Answer 2

@satellite73 @phi

Answer 3

this sounds like physics. do you have a formula for illumination ?

Answer 4

Yes. And I have no idea how to do it... I'm doing algebra 2 and they give me this. lol
\[l = S * D^-2 or l = S/D^2\]

Answer 5

Wait let me fix that... l = S * D^ -2 or l = S/D^2

Answer 6

ok, I assume D is distance from the light. what is S ?

Answer 7

I is the illumination at a certain point, S is the strength of the light source, measured in watts or kilowatts, and D is the distance of the point from the light source. The superposition principle states that the total illumination received at a given point from two sources is equal to the sum of the illuminations from each of the sources.

Answer 8

so S for lighthouse A is 10 kW
and S for lighthouse B is 20 kW

the superposition stuff means you add the illumination from both lighthouses.

Answer 9

For question 2, what is the distance of the man from lighthouse A ?

Answer 10

OK so 30 kW

Answer 11

6KM

Answer 12

Well, it doesn't say. He's not yet at point C.

Answer 13

we don't add the S's we add "illumination" = S/D^2

***
Well, it doesn't say. He's not yet at point C.
***
they do say. But it is a letter not a number.

Answer 14

What do you mean it's a letter not a number? Ohhhh x. lol

Answer 15

I'm slow today...

Answer 16

so when the distance from lighthouse A is x, what is the illumination (just from A) ?

Answer 17

x

Answer 18

10x?

Answer 19

use the formula they gave you
\[ I = \frac{S}{D^2} \]

Answer 20

\[10/x^2\]

Answer 21

ok, now you need to find the illumination from lighthouse B

The first step is find the distance to lighthouse B
do you know how to do that ?

Answer 22

I'm not sure...