Scale reading when elevator is decelerating upward

[khf]

A 56-kg girl weighs herself by standing on a scale in an elevator. What does the scale read when the elevator is ascending at 13m/s buts its speed is decreasing by 4m/s in each second?

I know you use Newton's second law, however, I do not know how to find acceleration..

 

[Phymath]

which direction is the acceration? If you figure that out you know which direction the force of the slowing elevator is. Add the wieght vector with the force vector to get her wieght...




the acceration if opposite the velocity ( girl weighs W = mg + ma_elevator)

 

[Doc Al]

I know you use Newton's second law, however, I do not know how to find acceleration..

Apply the definition of acceleration: $a = \Delta v/\Delta t$. (Direction matters.)