velocity

[student000]

A 2.0 kg particle is moving along the x axis to the left with a velocity of v= -6.0 m/s. Suddenly, between times t =0 and t = 4.0 x a net force = 3t^2 – 12t is applied to the particle, where F is in N and t is in s. Calculate the velocity of the particle at t=4.0 s.
I am having trouble making the numbers work. Thanks

[diazona]

Well, what have you tried so far?

[student000]

Someone told me to use this formula but I don't understand why the 4 is in the first equation because the mass is 2 kg

[student000]

Sorry, the formula is
a= force/mass= (3t^2-12t)/4

Why is there a 4?