Answer:
v = 8[m/s]
Explanation:
In this case, the work that is exerted on the cart is the kinetic energy that allows the movement, so we can use the following equation of kinetic energy.
[tex]E_{kin}=Work\\E_{kin}=\frac{1}{2} *m*v^{2}[/tex]
Now replacing:
[tex]128=0.5*4*v^{2} \\v=\sqrt{64} \\v=8[m/s][/tex]
