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TBR Physics Book II page 152 # 1
“In order for an oil drop of mass m, radius r, and charge density rho to be suspended between the plates [this is the Oil drop experiment], the magnitude and direction of the electric field must be___”
Answer: 3mg / (4*pi * rho* r^3) downward
TBR basically finds the answer be process of elimination (that m must be in the numerator) which I understand. But can anyone actually show how to find this answer mathematically?*
The only formula given is deltaV = E * L where E is electric field and L is plate separation distance
*I know MCAT is all just about finding the right answers but I don’t know if on the real AAMC tests, the answer choices will be able to be eliminated as easily as this TBR question.
“In order for an oil drop of mass m, radius r, and charge density rho to be suspended between the plates [this is the Oil drop experiment], the magnitude and direction of the electric field must be___”
Answer: 3mg / (4*pi * rho* r^3) downward
TBR basically finds the answer be process of elimination (that m must be in the numerator) which I understand. But can anyone actually show how to find this answer mathematically?*
The only formula given is deltaV = E * L where E is electric field and L is plate separation distance
*I know MCAT is all just about finding the right answers but I don’t know if on the real AAMC tests, the answer choices will be able to be eliminated as easily as this TBR question.
