Can you guys tell me if any of these are wrong? My science teacher said some were but I’m not sure which ones

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.

Each line (unit) on the horizontal axis represents: 5 years 10 years 20 years all of the above

Pls ! what are 3 examples of acceleration that doesn’t involve a change in speed ?