Calculating Acceleration and Work for a Box on a Horizontal Surface

[kselanders]

Homework Statement

A 125 N box is pulled along the floor with a force of 60 N acting at an angle of 42 degrees to the horizontal. If the force of friction on the box is 15 N,
A. what is the acceleration of the box?
B. How much work is done to move the box over a distance of 5 m?

Homework Equations

The Attempt at a Solution

TX = Tcos0
TX = 60Ncos42
TX = 44.6N

fnet=60N - 45N
fnet = 45N

fnet= TX - Ff = ma
45N = 44.6N - 15N = (125N)(a)
45N = .237 = a
a=189.9m/s^2

 

[MillerGenuine]

fnet= TX - Ff = ma
45N = 44.6N - 15N = (125N)(a)
45N = .237 = a
a=189.9m/s^2

you should only have 44.6-15N= ma
Where are you getting the 45N on the left hand side of the equation?
Also, remember that the "m" in F=ma is the MASS of the object...What are units of mass? 125N is not a mass.