1) A spherical surface completely surrounds a collection of charges. Find the electric flux through the surface if the collection consists of a single +3.93E-6 C charge.

Question

2) A plate carries a charge of -2.52μC, while a rod carries a charge of +2.19μC. How many electrons must be transferred from the plate to the rod, so that both objects have the same charge.

3) Two charges are placed on the x axis. One of the charges (q1 = +8.06 μC) is at x1 = +2.79 cm and the other (q2 = -21.8 μC) is at x1 = +8.94 cm. Calculate the net electric field at x = 0 cm.

4)Two tiny conducting spheres are identical and carry charges of -19.8 μC and +49.8 μC. They are separated by a distance of 2.52 cm. What is the magnitude of the force that each sphere experiences?

Can somebody please help me! i got one try on each left... they're annoying me, i know im making little mistakes.. if you want me to show work i will!. here is what i did on question 4) keep getting this answer -1.395 (which is wrong) and i used F = 8.99E9 *Q1*Q2/r²
IDK WHATS WRONG!

THANK YOU SOO MUCH TO WHO EVER ANSWERS THIS!!

Answer 1

On number 4, just looking at your answer, order of magnitude, you have to be wrong.
F=8.99E9*19.8E-6*49.8E-6/(2.52E-2)^2 which is about 10,000 times larger than your answer

Answer 2

I would suggest on the other three, do them on paper, check the orders of magnitudes, then verify it on the calc.