Answer:
10 m/s
Explanation:
The problem can be solved by using the law of conservation of momentum: the initial momentum has to be equal to the final momentum, so we can write the following
[tex]p_i = p_f[/tex]
[tex]m_1 u_1 + m_2 u_2 = (m_1 +m_2 )v[/tex]
where
[tex]m_1 = 10,000 kg[/tex] is the mass of the first car
[tex]u_1=30 m/s[/tex] is the initial velocity of the first car
[tex]m_2 = 20,000 kg[/tex] is the mass of the second car
[tex]u_2 = 0[/tex] is the initial velocity of the second car
[tex]v[/tex] is the final velocity of the two combined cars after the collision
Re-arranging the equation and substituting the numbers, we find
[tex]v=\frac{m_1 u_1 +m_2 u_2}{m_1+m_2}=\frac{(10,000)(30)-0}{10,000+20,000}=10 m/s[/tex]
