- #1

jgray

- 10

- 0

## Homework Statement

A 90 kg box is pushed by a horizontal force F at constant speed up a ramp inclined at 28°, as shown. Determine the magnitude of the applied force.

when the ramp is frictionless.

when the coefficient of kinetic friction is 0.18.

## Homework Equations

Ff= uk(Fn)

## The Attempt at a Solution

I think I have the answer to part 1 complete and correct: I tilted the axis and ended up multiplying sin28degrees(90kg)(9.8m/s^2) to give me 414N for the applied force.

Im not sure about the second part though, where I have friction involved. I tried finding my force of friction --> (0.16)(882N) = 141 N, then subtracting it from my initial applied force I found - so 414N - 141 N gives me 273 N. Not sure if this is correct though.. Help please!