Could i please have help with this ? Please use proper significant figures for right answer, thank you.

Question 1 The thin rod shown below has been bent into a perfect semicircle with radius R2114 cm. It carries a total charge of Q: 2.40 nC. What is the electric potential at the center of the semicircle? \\\\..-Ccnlcr Charge Q Question 2 A proton is fired towards a plastic bead charged to +2.25 nC from far away. If the initial speed of the proton is 7.00 x105 mfs , what is the closest the proton gets to the bead (measured from the center of the bead)