Question

A 20kg block is attached on a spring with a spring constant of 900N/m. If the given object is pull to the right with the floor having a friction coefficient of 0.5, what is the maximum distance you can pull the block that the friction force can handle before the spring starts sliding back?

Answer 1

$$F=F_{fr},$$ $$kx=\mu mg,$$ $$x=\dfrac{\mu mg}{k}=\dfrac{0.5\cdot20\ kg\cdot9.8\ \dfrac{m}{s^2}}{900\ \dfrac{N}{m}}=0.11\ m.$$