The SI system, also called the metric system, is used around the world. There are seven basic units in the SI system: the meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd).
The period is the temporal difference between two same points in consecutive waves
E = 0.5mv^2 = 0.5*44*10^2 = 2200J
An electric force exists between the following:
-Two negative objects
-Two positive objects
-A negative object and a positive object