I set up the equation.Quote:

A railroad flatcar of weight 7840Ncan roll without friction along a straight horizontal track. Initially, a man of weight 596Nis standing on the car, which is moving to the right with speed 25m/s; see the figure. What is the change in velocity of the car if the man runs to the left so that his speed relative to the car is 8.0m/s?

[math ]m_1*v_1_i+m_2*v_2_i=m_1*v_1_f+m_2*v_2_f[/tex]

[math ]0+0=\frac{596}{9.8}*8+\frac{7840}{9.8}*v_2_f[/tex]

I came out with the answer -.076 m/s. Can anyone confirm this?