An oil drop (m = 1.6 x 10-16 kg) is suspended between plates separated by 1.8 cm. The voltage across the plates is 125 V. Is this possible?

E = V / d       125 V / .018 m = 6940 V/m     electric field

F = E Q       force on Q due to E

F = E n e     where n is the number of electrons in Q

m g = E n e

n = m g / E e     where n is the number of electrons e needed to support drop

n = 1.6 * 10E-16 * 9.8 / (6940 * 1.6 * 10E-19)

n = 1.41

Since n needs to be an integral number of charges, the drop would

not be suspended (motionless under these conditions).

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.

i think the answer is a and b

i wish you luck