physics
posted by julia on .
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.
Is this formula right?
a= force/mass= (3t^212t)/4
v(4)=12+a*t
now put t=4 into the equation
I get the acceleration as 0!!!

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.
Is this formula right?
a= force/mass= (3t^212t)/2
if so, I get 0
How do I find the velocity at 4s?