some friction test i need help with?

Question

a box is being pushed across an elevator floor.
the pushing force is 3.14 N
the elevator is accelerating upwards at 0.55 m/s^2
what is the coefficent of kinetic friction?

much appreciated <3

mass of box = 1 kg

Answer 1

f=uN

N= W+F (since elevator is accelerating upward )
N=mg +ma
Assuming that the pushing force equal to the force of friction
u= f/N
u= f/m(g +a)
u=3.14/m(9.81 + 0.55 ) so what was the mass of the box?

Answer 2

You are missing some numbers, like the mass/weight of the box, or whether the box is moving with a constant velocity or acceleration. I will do this problem as though it is moving at a constant speed.
FBD of the box:

Sum of the forces horizontal = 0 = F - friction
Sum of the forces vertically = 0 = N - m*(g+a)
N = m*(g+a)

We know that friction = u*N = u*m*(g+a)
Insert that into the horizontal

0 = F - u*m*(g+a)

Solve for u

u = F/(m*(g+a))