posted by nada
A spring lies on a horizontal table, and the left end of the spring is attached to a wall. The other end is connected to a box. The box is pulled to the right, stretching the spring. Static friction exists between the box and the table, so when the spring is stretched only by a small amount and the box is released, the box does not move. The mass of the box is 0.85 kg, and the spring has a spring constant of 77 N/m. The coefficient of static friction between the box and the table on which it rests is μs = 0.60. How far can the spring be stretched from its unstrained position without the box moving when it is released?