Question

Large electric fields in cell membranes cause ions to move through the cell wall. The field strength in a typical membrane is 1.0 times 10^7 N/C. What is the magnitude of the force on a calcium ion with charge +e? Express your answer using two significant figures.

Answer 1

Answer:

$1.6\cdot 10^{-12}N$

Explanation:

The electric force on a charged particle is given by

$F=qE$

where

q is the charge of the particle

E is the strength of the electric field

In this problem, we have

$E=1.0\cdot 10^7 N/C$ is the electric field strength

$q=+e=+1.6\cdot 10^{-19}C$ is the charge of the calcium ion

Therefore, the electric force exerted on the calcium ion is

$F=(1.6\cdot 10^{-19}C)(1.0\cdot 10^7 N/C)=1.6\cdot 10^{-12}N$