Part b–short problems11. the electric potential at a certain point is space is 12 v. what is the electric potential energy of a –3.0 c charge placed at that point? a) +4 jb) –4 jc) +36 jd) –36 je) zero μj12. a completely ionized beryllium atom (net charge = +4e) is accelerated through a potential difference of 6.0 v. what is the increase in kinetic energy of the atom? a) zero evb) 0.67 evc) 4.0 evd) 6.0 eve) 24 ev14. a conducting sphere has a net charge of –6.4 × 10–17c. what is the approximate number of excess electrons on the sphere

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?