Can someone answer these or walk me through them

Problem Three

The ks, rs, q1, q2 all cancel out.

You are left with F2/F1 = 9/1

The answer is C

Problem Four

This problem is a bit harder.  In the first place one of the charges must be - otherwise the force will not be an attractive one which is what the question implies. So let q < 0.

That aside, I don't know how the acceleration could be a constant. As the distance decreases the force increases and therefore so does the acceleration. But it is is not a constant.

I would say that the answer is B.

search it up!

explanation: