Calculate the centripetal force on the end of a 100 m wind turbine blade that is rotating once every 7 seconds. assume the mass is 4 kg.

Centripetal force is the force on an object on a circular path that keeps the object moving on the path. It is always directed towards the center and its magnitude is constant, based on the mass of the objects, its tangential velocity and the distance of the object from the center of the circular path (radius)
Fc = mv²/r 
 m is 4 kg, r = 100 m, the velocity is (2πr/7) = 89.80 m/s.
Thus centripetal force =( 4× 89.8²)/100
                                    = 322.562 N

Your answer is c. explanation: plasma  is the fourth state of matter, derived from the gaseous state of matter.  plasma  can contain free  electrons  and/or  ions. while  plasma is never neutral, it can either be positively or negatively charged.  gases, however, are electrically neutral.