Charged, Insulating Sheet question

[StudentA1]

1. a sphere with mass 4.00 kg and charge of
5.00 C hangs from a thread near a very large, charged insulating sheet. The
sheet is to the left of the sphere, and the sphere is is attracted toward the sheet, to the left. The charge density on the surface of the sheet is uniform and equal
to 2.50 C/ meters squared. Find the angle of the thread.

Homework Equations

3. I was able to solve the problem, but I don't understand why the sphere is attracted to the sheet, considering that the sheet an sphere both have positive charge on them. Shouldn't the electric force due to the sheet repel the sphere to the right, instead of attract it to the left?

 

[TSny]

Yes, you are right. If both objects are positively charged, they will repel.

 

[StudentA1]

okay, but the solution that my teacher gave
for this problem says that the
charged sheet attracts the mass to it,
pulling the mass to the left. Shouldn't
the sheet push the mass to the right?