Question

The Richter scale is used to measure the magnitude of an earthquake. The magnitude, R, is given by the earthquake. Determine the amount of energy released be an earthquake of magnitude of 7.5. Rewrite the equation for the magnitude of an earthquake , using the magnitude of 7.5 given in the problem.

Answer 1

You'll have to provide more information. The required conversion from Richter Scale Magnitude to Energy Released is not common knowledge.

Answer 2

the equation is R=0.65log(0.39E)+1.45

Answer 3

Where "E" is the energy? Okay, solve that equation for "E".

Answer 4

it doesnt say to solve it, but would the new equation look like this 7.5=0.65log(0.39E)
+1.45

Answer 5

Well, since you have R and not E, how else do you plan to find E?

Solve it for E. Substitute 7.5 for R first, if you like, but solve for E.

Answer 6

does E=-0.07

Answer 7

Not sure. I didn't work the problem. However, if we are talking about energy release, it is unlikely to be a small number and also unlikely to be negative.

Solve for E and SHOW YOUR STEPS. Just one piece at a time.

7.5=0.65log(0.39E)+1.45

Subtract 1.45

7.5 - 1.45 =0.65log(0.39E)
6.05 =0.65log(0.39E)

Now what?

Answer 8

6.05=-0.19(0.39E)
6.05=-0.07E
find LN of 6.05
1.8=-0.07E
than divide both sides by -0.07
-25.71=E

Answer 9

is this correct @tkhunny

Answer 10

I need help solving this equation @Psysom

Answer 11

This problem @Psymon its to long to write again.

Answer 12

So I'm guessing
\[7.5 = 0.65\log(0.39E) + 1.45\]
Is the starting point.

Answer 13

got that but tkhunny told me to solve for E and never responded back

Answer 14

Well, this means we want to isolate the log term first. So I will subtract 1.45 from both sides then divide by .65.

Answer 15

or subtract both sides by 1.45

Answer 16

Doing that gives us:
\[9.31 = \log(0.39E)\]
And yes, I subtracted the 1.45 first, I mentioned that :P

Answer 17

so its not asking me to solve the problem it says to Rewrite the equation for the magnitude of an earthquake , using the magnitude of 7.5 given in the problem.

Answer 18

So now by log rules:

\[x = \log_{b}M \] is the same as
\[b ^{x} = M\] Now when the base is not written with the log, we assume it to be base 10. So because of our log rule, we are being told this:
\[10^{9.31} = 0.39E\]

Answer 19

you gave me the answers to another question i have. Simplify the problem so that it is written in the form b=loga.

Answer 20

Haha. Interesting. Well, what I put up there should be the answer. 10^(9.31)/.39

Answer 21

always thinking a head.

Answer 22

ok ya now its asking me to solve the equation.

Answer 23

Right, which is what I just posted :P 10^(9.31)/0.39. Pretty massive number o.o

Answer 24

so i solved it wrong in the equation above.

Answer 25

I would say so, yeah. Somehow a -0.19 came out of nowhere O.o

Answer 26

you now how it has log on the calculator i did that for 0.65.

Answer 27

Well, the 0.65 is just multiplying the log, it has nothing to dowith the log itself. You need to isolate the log term first. Just like you would isolate x in an algebraic equation, you want to isolatethe log term. Which means I divided both sides by 0.65.

Answer 28

when i divide i get 9.38

Answer 29

Sorry, had to be away x_x So wait, (7.5 - 1.45)/.65 and you got 9.38?

Answer 30

Yeah, I still get 9.31

Answer 31

ok thank u.

Answer 32

Mhm. And then once you have the log expression by itself, you can use the log property I mentioned to get your answer :3

Answer 33

@Psymon how would u solve 10^9.31?

Answer 34

Calculator. Nothing much else you could do.

Answer 35

i got a really big number

Answer 36

You should xD

Answer 37

And then it's divided by .35

Answer 38

0.39 u mean?

Answer 39

Whatever the number was, sorry x_x

Answer 40

its fine just in case i skiped i step or something.

Answer 41

Right. But no, the number is supposedtobe massive it seems. I solved for it on my calculator justto check.

Answer 42

all right my final answer is 5235225499

Answer 43

Seemingly, yes. I mean think of it, an earthquake is a massive force, not surprised the energy level would be massive.

Answer 44

got it.

Answer 45

cool, cool ^_^