# Very very noob calculation verification [BEDMAS]

1. Aug 9, 2010

### seto6

1. The problem statement, all variables and given/known data

3. The attempt at a solution
i calculated and got like

x'=3.291*104 ---->this does not match with answer key, but im sure its correct.
could some one verify this pls

t'=-4.618*10-5---. this makes sense

2. Aug 9, 2010

### diazona

It can't be correct, it doesn't have the right units.

What calculation did you do? Show your work...

3. Aug 9, 2010

### seto6

i did the exact thing as the solution, i think they converted the x'=32917.5m to x'=32.9km and did not indicate it...

4. Aug 9, 2010

### novop

x' should be less than x. t' should be greater than t. Also a negative time interval doesn't make sense.

Last edited: Aug 9, 2010
5. Aug 9, 2010

### seto6

-ve means it happend before no?

6. Aug 9, 2010

### diazona

They're the same thing (except for rounding), it's not necessary to indicate anything for that conversion.

And a negative time interval could make sense, if it's the time difference from A to B and B happened before A.

Anyway, I still don't see your work. Unless the image you show is actually the work you did? I thought it was the given solution.

7. Aug 9, 2010

### diazona

Aha: I just checked the calculations in the image you showed. I can't say whether the calculation is set up correctly, but there is definitely an error. When I plug
$$(1.155)\bigl[3.0\times 10^4\,\mathrm{m} - (0.5)(3.0\times 10^8\tfrac{\mathrm{m}}{\mathrm{s}})(1.0\times 10^{-5}\,\mathrm{s})\bigr]$$
into my calculator, I get $32.9\,\mathrm{km}$. So the result shown in the image is off by a factor of 1000 - probably whoever did that calculation wrote the wrong units on the result.

8. Aug 10, 2010

### seto6

its from a solution Manuel. im 100% sure its wrong off by a factor of 1000

9. Aug 10, 2010

### seto6

as i think is said it the solution give nis the same as my work that how i did it then when i looked at solution it was the same but off by 1 factor of 1000..so i was confused so i asked thanks for the help