Physics - W.E.P. Question with Solution | TestHub

Let spring is compressed by a length $x$. Kinetic energy of ball = Potential energy of spring $ie,\frac{1}{2}m{v}^2=\frac{1}{2}k{x}^2$ Given, $m=2\mathrm{kg},v=3\mathrm{m}/\mathrm{s},k=144\mathrm{N}/\mathrm{m}$ $\therefore \frac{1}{2}\times 2\times (3{)}^2=\frac{1}{2}\times 144\times x^2$$\therefore x=\sqrt{\frac{9}{72}}=\frac{1}{2\sqrt{2}}\mathrm{m}$ Hence, length of compressed spring $=2-\frac{1}{2\sqrt{2}}$ $=\frac{4\sqrt{2}-1}{2\sqrt{2}}$ $=1.5\mathrm{m}$