# Electric Force Textbook error?

1. Jan 27, 2013

### quicksilver123

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

Find the net force given a point charge and the value of the electric field.

2. Relevant equations

FE = εq

ε= (5.6*10^4)
q=(-1.2 * 10^-5)

3. The attempt at a solution

FE = εq
FE = (5.6*10^4)(-1.2 * 10^-5)
FE = 0.672 N

Seriously. I am posting this question.

Here's the answer the book gave:

FE = εq
FE = (5.6*10^4)(-1.2 * 10^-5)
FE = (6.7*10^4) N

It does this again on the answer to the next question, increasing the magnitude by 10^5.

Everything I know tells me I'm right but I need to be sure I'm not doing something very wrong. I don't know why this text is still in circulation if its riddled with this many errors.​

2. Jan 27, 2013

### Staff: Mentor

Did the question supply units to associate with the field and charge values?

3. Jan 27, 2013

### quicksilver123

xxxx

Last edited: Jan 27, 2013
4. Jan 27, 2013

### quicksilver123

charge is in coulombs

field is in newtons per coulomb

5. Jan 27, 2013

### quicksilver123

xxxx

Last edited: Jan 27, 2013
6. Jan 27, 2013

### Staff: Mentor

So, coulombs for charge, meters for distances. Looks like your answer is correct and the text is in error.

7. Jan 27, 2013

### quicksilver123

Thanks.

Kind of frustrating, seeing as how we're expected to learn the course solely from the text... which is very inaccurate a lot of the time.

8. Jan 27, 2013

### Hakkinen

What is the text, Halliday and Resnick?

9. Jan 27, 2013

### quicksilver123

Nah. This place makes their own text for Canadian students.