Three 3.0g {\rm g} balls are tied to 80-cm {\rm cm}-long threads and hung from a single fixed point. Each of the balls is given the same charge q q. At equilibrium, the three balls form an equilateral triangle in a horizontal plane with 20 cm {\rm cm} sides. What is q?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)