you write the equation of motion
the movement is 1-dimensional so you only need 1 equation
you got , and in the text
you find with Newton's 2nd law
A 26 kg box is being pushed across the floor by a constant force <103,0,0> N. The coefficient of kinetic friction for the floor and box is .18. At t=6 s the box is at location <10,4,-4>m, traveling with velocity <7,0,0>m/s. What is its position and velocity at t-7.6s?
I don't know where to start help please?