Physics - Center of Mass Question with Solution | TestHub

According to the principle of conservation of linear momentum, the total momentum before the collision is equal to the total momentum after the collision. Let $m_1=2\text{ kg}$, $u_1=5\text{ m/s}$, $m_2=3\text{ kg}$, $u_2=0\text{ m/s}$. After collision, the blocks stick together and move with a common velocity $V$. So, $m_1{u}_1+m_2{u}_2=(m_1+m_2)V$. Plugging in the values, $(2\text{ kg})(5\text{ m/s})+(3\text{ kg})(0\text{ m/s})=(2\text{ kg}+3\text{ kg})V$. This gives $10=5V$, so $V=2\text{ m/s}$.