I know f=ma but I need velocity

[sjcorona]

While two forces act on it a particle is to move at the constant velocity v= (3m/s)I - (4m/s)j. One of the forces is F1=(2n)I +(-6n)j what is the other force?


I want to say (1n)I + (2n)j but then I couldn't decided why that would be true. I guess I liked those numbers because if the mass were 1kg it would make the acceleration fit the requirements, I don't think I'm thinking about it correctly.

 

[CWatters]

Have a think about how Newtons first law would be applied to this situation.