What is the Normal Force Exerted by a Girl Pushing a Lawn Mower?

[Laurili]

Homework Statement

:[/B] A girl pushes a 24 kg lawn mower as show in the figure. (figure shows a girl pushing a manual push mower. The force is going down the handle and theta is from the ground to the mower.) Force=25N and theta=34 degrees. Ignore friction. Gravity does apply at 9.8 m/s^2

Homework Equations

:[/B] I already found the acceleration and checked it to make sure it was right. Acceleration was found to be 0.86 m/s^2

The Attempt at a Solution

:[/B] I first tried to find out if Fy was greater or less than mg by; Fy=25N times sin34 degrees which equaled 13.98N and mg=24kg times 9.80 m/s^2= 235.2N Then I set up the sum of the forces as; Fy+ Fn - mg= 0 ( 13.98N) + Fn - (235.2N)= 0 I found the normal force to be; Fn= 221.22N My problem is once i submitted this answer I was told I was wrong. Any help is appreciated, thanks

 

[fzero]

You have a sign wrong. Draw the force diagram, determine the directions of all forces and then recheck your equation.