A light elastic string with natural length $0.4\,\text{m}$ and modulus of elasticity $20\,\text{N}$ has one end fixed at point $O$. Its other end is connected to a particle $P$ of mass $0.25\,\text{kg}$. The particle $P$ hangs at rest in equilibrium below $O$.
(i)[2]
Calculate the value of the distance $OP$.
(ii)[3]
Particle $P$ is lifted and then released from rest at $O$. Calculate the speed of $P$ as it passes through the equilibrium position.
(iii)[3]
Calculate the largest possible value of the distance $OP$ in the later motion.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Using $T = \frac{\lambda x}{L}$ gives $0.25g = \frac{20e}{0.4}$” …