The same balloon which has a charge of 7.2 nC is brought close to another student's hair who's charge is unknown. The force experienced is 152 N and the distance between the balloon and

hair is 0.15 m. What is the charge on the student's hair (the second charge)?

the answer is a. hope this .

i think the answer is a and b

i wish you luck

the moving of the box is a result of centripetal force. think of that  as a car or a truck in this case creates a turn, the force of friction performing upon the turned wheels of the car runs centripetal force obligatory for circular motion for the things inside it.