Magnitude of acceleration

[bearhug]

A block of mass 7.0 kg is pulled along a horizontal frictionless floor by a cord that exerts a force of 37.0 N at an angle 34.1° above the horizontal. What is the magnitude of the acceleration of the block?
What is the magnitude of the normal force exerted on the mass by the floor?

I've been having trouble with these kind of problems. The equations in my book aren't very well explained, basically the book doesn't explain where these equations are coming from. This is the main reason why I'm having a hard time with these kind of problems. Anyway for the first question I thought that F=ma so I plugged in mass and the force to get acceleration, but I believe that is wrong. Any help as to what equations I need to use maybe with explanations would be a great help.

[Doc Al]

Since the block only moves horizontally (the forces in the vertical direction will add to zero) you need to use the horizontal component of the force on the block to find its acceleration.

[oscarkool2]

Ok but once you have the acceleration, how do you find the magnitude of it? Sorry for necroing this, but I have the same exact question. Magnitude of acceleration? Have no clue how to find that.

[Doc Al]

Vector quantities, such as acceleration, have both magnitude (an amount) and direction. Here they just want the magnitude, so forget about direction.