Given
Mass of one object, m=4 kg
Velocity of the object, u=29 m/s towards the right
Mass of the other object, m'=11.5 kg
Velocity of the other object, u'=18 m/s towards left
After collision
The object with mass 11.5 kg moves at a speed, v'=4 m/s towards right
To find
The velocity of the object with mass 4 kg after collision
Explanation
Let the direction towards right be positive
By conservation of momentum
[tex]\begin{gathered} mu+m^{\prime}u^{\prime}=mv+m^{\prime}v^{\prime} \\ \Rightarrow4\times29-11.5\times18=4v+11.5\times4 \\ \Rightarrow v=-34.25\text{ m/s} \end{gathered}[/tex]
Conclusion
The velocity of the object is C.-34.25 m/s
