Calculating Applied Force in an Accelerating Elevator

[anubis01]

Homework Statement

You are riding in an elevator on the way to the eighteenth floor of your dormitory. The elevator's upward acceleration is a= 1.84 . Beside you is the box containing your new computer; box and contents have a total mass of 28.9 kg. While the elevator is accelerating upward, you push horizontally on the box to slide it at constant speed toward the elevator door.

a)If the coefficient of kinetic friction between the box and elevator floor is u_k= 0.31, what magnitude of force must you apply

Homework Equations

n=mgcosθ

The Attempt at a Solution

f_y=n-mg=ma
n=m(a+g)=336.396
f_k=un=0.31*336.396=104.28

I think this is the solution but I'm not entirely sure. As always any help is appreciated.

 

[PhanthomJay]

Yes, looks good. But don't forget the proper units for the force.

 

[anubis01]

thanks for te vote of confidence, I was a little worried I was wrong but I'm right thankfully :)