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 $45\sqrt 2 \,m{s^{ - 1}}$ each, the velocity of their combined mass after collision is .................. $\mathrm{m} / \mathrm{s}^{-1}$
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 $45\sqrt 2 \,m{s^{ - 1}}$ each, the velocity of their combined mass after collision is .................. $\mathrm{m} / \mathrm{s}^{-1}$
$45\sqrt 2$
$45$
$90$
$22.5\sqrt 2$
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 $45\sqrt 2 \,m{s^{ - 1}}$ each, the velocity of their combined mass after collision is .................. $\mathrm{m} / \mathrm{s}^{-1}$
Initial momentum
$\vec P = m45\sqrt 2 \;\hat i + m45\sqrt 2 \;\hat j$ $⇒$ $|\vec P| = m \times 90$
Final momentum $2m \times V$
By conservation of momentum $2m \times V = m \times 90$
$V = 45\,m/s$