A2-kg book falls off a shelf. it hits a student traveling 2 m/s. how much kinetic energy does the book have?

8 j

2 j

1 j

4 j

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.