Pushing a lawn mower, total force exerted?

[tbaskerv]

Homework Statement

A person pushes a 13.0 kg lawn mower at constant speed with a force of 77.0 N directed along the handle, which is at an angle of θ = 49.0° to the horizontal.

Calculate the force the person must exert on the lawn mower to accelerate it from rest to 1.8 m/s in 2.0 seconds with a retarding force of -50.5 N in the x direction.

Homework Equations

Using LaTeX Code: v^2 = v_0^2 + 2 a \\Delta x I found a = 0.81 m/s^2

The Attempt at a Solution

Using the acceleration of 0.81 m/s^2 times 13 kg I get F = 10.5 N, now I think I'm supposed to add the retarding force, but 61 N isn't correct.
Did I miss something?
Found the retarding force by finding the Fpcos(49) = 50.5 (in the x direction) Fp = 77.0 N.
Beyond that I'm lost. Please help

 

[tbaskerv]

Nevermind, another problem helped me out, thank you! More will come!