Question

3. A massless spring is attached to a fixed support on one end and has a 2 uC charge glued to the other end. A -4 HuC charge is slowly brought near. The spring is stretched 1.2 cm when the two charges are 2.6 cm apart. What is the spring constant of the spring?

Answer 1

$k'x=\frac {kq_1q_2}{d^2}$

$k'=\frac {kq_1q_2}{xd^2}$

$k'=\frac {9\cdot 10^9\cdot 2\cdot 10^{-6}\cdot 4\cdot 10^{-6}}{1.2\cdot 10^{-2}\cdot (2.6\cdot 10^{-2})^2}$

$k'=8875.74\: N/m$