MCQ
Two putty balls of equal mass moving with equal velocity in mutually perpendicular directions, stick together after collision. If the balls were initially moving with a velocity of $45 \sqrt{2} \mathrm{~ms}^{-1}$ each, the velocity of their combined mass after collision is
- A$45 \sqrt{2} \mathrm{~ms}^{-1}$
- ✓$45 \mathrm{~ms}^{-1}$
- C$90 \mathrm{~ms}^{-1}$
- D$22.5 \sqrt{2} \mathrm{~ms}^{-1}$

