Coulomb ( Electric force and charge )

[asz304]

Homework Statement

1. [1pt]
What is the total charge of the radon nucleus? (The neutral radon atom has 86 electrons.)

1.38 * 10^-17 C


2. [1pt]
What is the magnitude of its electric field at a distance of 9.6 x10-10 m from the nucleus?

+1.34 * 10^11 V/m

3. [1pt]
What is the magnitude of the force on an electron at that distance?

Homework Equations

F=qE

q = +/- 1.60 * 10^-19 C

The Attempt at a Solution

F = (- 1.60*10^-19C)(1.34*10^11 V/m )
= 2.10*10^-8 N

I tried to use + and -ve C to get my answer, but the computer told me I got the wrong answer. Is there something that I'm missing?

Thanks

 

[cupid.callin]

even i got same answer