## osanseviero one year ago Electricity problem (Coulomb's Law)

1. osanseviero

Two identical balls with no initial charge are connected with a string (k = 25 N/m) that is 1m long. Then the balls get charged with q and -q. The string now is 0.635m long. Which is the value of q?

2. IrishBoy123

"string" ?!?! you mean spring ??!!?? use force or energy and Coulombs Law and Hooke's Law using FORCE: you have $$\large |F| = k_c \frac{q_1 \ q_2}{r^2} = k_c \frac{q^2}{r^2}$$ from Coulomb and $$\large |F| = k_{spring} \ x$$ in equilibrium you are balancing the attractive force of the balls and the restorative force of the spring

3. osanseviero

That is simple, thanks a lot :)