Answer: In the exercise there are lost data, but I already found the exercise in a book
qsoot= 6.66e-18
no. electrons = approximately 42 electrons
Explanation:
msoot = 1.2e-12 kg
qcollector = 2e-06 C
rcollector = 0.1 m
The electric force must be equal to the weigth, so:
W=msoot*g (1)
Felec = k*qsoot*qcollector/r^2 (2)
equaling (1) and (2):
msoot*g = k*qsoot*qcollector/r^2 (3)
reorganizing the equation (3) and clear qsoot:
qsoot = (msoot*g*r^2)/(k*qcollector)
qsoot= 6.66e-18
no. electrons = qsoot / qelectron
no electrons = 41.6 electros (approximately 42 electrons)
