A light elastic string with natural length $0.4\,\text{m}$ has one end fastened to the fixed point $O$. Its other end is attached to a particle of weight $5\,\text{N}$, and the particle is in equilibrium $0.6\,\text{m}$ vertically below $O$.
(i)[2]
Find the modulus of elasticity of the string.
(ii)[3]
The particle is projected vertically upwards from the equilibrium position and comes to instantaneous rest after moving $0.3\,\text{m}$ upwards. Calculate the speed of projection of the particle.
(iii)[3]
Calculate the greatest extension of the string 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: “Use Hooke’s law in the form $5=0.2\lambda/0.4$” …