Newton's Laws of Motion PROBLEM!

[SOLVED] Newton's Laws of Motion PROBLEM!

A gardener pushes down along the handle of a lawn mower of 20 kg mass with a force of 150 N. The handle makes an angle of 60 degrees with the ground. Calculate the horizontal acceleration of the mower if the coefficient of kinetic friction between its wheels and the gound is 0.20.

Attempt:
I've gotten this equation so far but I'm confused on what to do next!

Fn = mg + FaSin$$\theta$$

= 20(9.8) + 150sin60

Fn = 326 N <---?