Physics Question from JEE Main 2026 · 23 January, Shift 1

In a perfectly inelastic collision, two spheres made of the same material with masses $15 \, \text{kg}$ and $25 \, \text{kg}$, moving in opposite directions with speeds of $10 \, \text{m/s}$ and $30 \, \text{m/s}$, respectively, strike each other and stick together. The rise in temperature (in $^\circ \text{C}$), if all the heat produced during the collision is retained by these spheres, is (specific heat $31 \, \text{cal/kg}\cdot{}^\circ\text{C}$ and $1 \, \text{cal} = 4.2 \, \text{J}$) :