Question in Inclined Planes

[collegelife101]

A 40-kg crate is being pulled along a frictionless surface by a force of magnitude 140 N that makes an angle of 30° with the horizontal. What is the acceleration of the crate?

I'm a little confused on why the PR is using the horizontal component of the force. I tried solving the problem by taking into account the force of gravity: fnet= 140-mgsin(theta).

Can someone please tell me why this is wrong?

Thanks!

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[collegelife101]

Nvm! I thought this question was referring to an inclined plane. Phew!