Q 11-04-123JEE MainJEE Main 2023 (6 Apr, Shift 1)Medium
A small block of mass $100\ \text{g}$ is tied to a spring of spring constant $7.5\ \text{N m}^{-1}$ and length $20\ \text{cm}$. The other end of spring is fixed at a particular point $A$. If the block moves in a circular path on a smooth horizontal surface with constant angular velocity $5\ \text{rad s}^{-1}$ about point $A$, then tension in the spring is
Answer: (A) $0.75\ \text{N}$
$kx=m\omega^2(l+x)$: $7.5x=0.1\times25(0.2+x)=0.5+2.5x\Rightarrow x=0.1\ \text{m}$.
$T=kx=0.75\ \text{N}$.
Solution by Sreeraj P, M.Sc Physics