A toy train of m=0.60 kg moves at 20m/s along a straight track. It bumps into another train of M=1.5kg moving in the same direction. They stick together and continue on the track at a speed 12 m/s. What was the speed in m/s of the second train just before the collision?

Respuesta :

Answer:8.8 m/s

Explanation:

Given

mass of train [tex]m_1=0.6 kg[/tex]

velocity of Train [tex]v_1=20 m/s[/tex]

mass of another train [tex]m_2=1.5 kg[/tex]

Final velocity of both train [tex]v=12 m/s[/tex]

Let [tex]v_2[/tex] be the velocity of [tex]m_2[/tex] before collision

As external Force is zero therefore change in momentum is zero

conserving Momentum

[tex]m_1v_1+m_2v_2=(m_1+m_2)v[/tex]

[tex]0.6\times 20+1.5\times v_2=(0.6+1.5)\cdot 12[/tex]

[tex]1.5\times v_2=25.2-12[/tex]

[tex]v=\frac{13.2}{1.5}=8.8 m/s[/tex]