The oil drop is negatively charged and weighs 8.5 10-15 N. The drop is suspended in an electric fi

The oil drop shown below is negatively charged and weighs 8.5 10-15 N. The drop is suspended in an electric field intensity of 5.3 103 N/C.
(a) What is the charge on the drop?


(b) How many electrons does it carry?

Known:
F= 8.5x10^-15N
E= 5.3x10^3 N/C
a) What is the charge on the drop?

E = F/q

So,
q = F/E

q= (8.5x10^-15N)/(5.3x10^3 N/C)
q= 1.6x10^-18C

(b) How many electrons does it carry?
q/qe
So,
q= 1.6x10^-18C and qe= 1.6x10^-19C

1.6x10^-18C/1.6x10^-19C

apx: 10 electrons