How much work done by friction when a box w/apparent mass...?

AI Thread Summary
The discussion focuses on calculating the work done by friction on a box with an apparent mass of 325 kg, moving horizontally with a coefficient of friction of 0.33, while being pulled at a 59.9-degree angle over 2.60 m. Participants clarify the concept of apparent mass, noting its distinction from volume and water displacement, and emphasize the need to determine the normal force to solve for frictional work. The equations of motion are applied, with a free body diagram illustrating the forces acting on the box. An attempt to calculate the applied force resulted in an incorrect value, prompting further guidance on using apparent weight as the normal force. The conversation concludes with a suggestion to equate apparent weight to the normal force for clarity in calculations.
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Homework Statement


How much work is done by friction when a box with an apparent mass of 325kg moves horizontally across a floor with coefficient of friction of .33 and is pulled at 59.9 degree angle for 2.60 m? What is the force that is pulling the box?

Homework Equations


W=Fdcos@ (@= theta)
Fnet=ma

The Attempt at a Solution


I searched for what apparent mass was, but what I found seemed to do with volume and water displacement, which aren't related to this problem. Instead I tried solving the second question first because I needed Normal force to solve the work done by friction.

For my free body diagram, I had force applied (Fa) in the y direction upwards on the y-axis along with normal force. Along the negative y-axis I had weight. Force of friction (Ff) was along the negative x axis, and force applied in the x direction was on the positive x axis.

In the x direction...
Ff=Facos@ (since no acceleration)
uN = FaCos@

In the y direction...
Fasin@ + N = W (again since no acceleration)
N= mg - FaSin@

So plugging in,,,
u(mg-Fasin@) = FaCos@

Solving for Fa I got...
umg-uFasin@ = Facos@
Fa= umg/(usin@ + cos@)
Fa= (.33*325 kg*9.8)/(.33sin59.9+cos59.9)
Getting that the force applied = 1335.50 N, but this is not correct.

Any help would be appreciated, thanks in advance.
 
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I found this on a Google search:
In physics, apparent weight is a property of objects that corresponds to how heavy an object is. The apparent weight of an object will differ from the weight of an object whenever the force of gravity acting on the object is not balanced by an equal but opposite normal force.
 
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If you assume ##apparent \ weight = mg - N## do you see a way to proceed?
 
anlon said:
If you assume ##apparent \ weight = mg - N## do you see a way to proceed?
Yes, thank you!
 
Try taking the apparent weight = N.
 
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