Energy lost from sphere due to spark

1. May 13, 2016

Janiceleong26

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

2. Relevant equations

3. The attempt at a solution
I did this :
1/2 (2.7x10^-6)(150x10^3) - 1/2 (1.575x 10^-6)(75x10^3) =0.143 J
But the answer is 0.15 , where did I did wrong?

Last edited: May 13, 2016
2. May 13, 2016

freddie_mclair

I think it is: [(1/2) x (2.7x150) - (1/2) x (1.35x75)]x10^-3 = 0.152 J

3. May 13, 2016

Janiceleong26

Oh whoops, I read off the point wrongly, thanks!