How Much Work Do Mules Perform Pulling a Barge?

[mparsons06]

Homework Statement

A barge of mass 5.0×104 kg is pulled along the Erie Canal by two mules, walking along towpaths parallel to the canal on either side of it. The ropes harnessed to the mules make angles of 45° to the canal. Each mule is pulling on its rope with a force of 1.2 kN. How much work is done on the barge by both of these mules together as they pull the barge 154 m along the canal?

Homework Equations

W = F(mule)*x*cos(theta)

The Attempt at a Solution

I found the work done by one mule, but am not sure if it's correct:

W = F(mule)*x*cos(theta)
W = (1200 N)*(154 m)*cos(45)
W = 1.31 x 10^5 J

If it is correct, how do I find how much work is done by both mules?

 

[PhanthomJay]

Homework Statement

A barge of mass 5.0×104 kg is pulled along the Erie Canal by two mules, walking along towpaths parallel to the canal on either side of it. The ropes harnessed to the mules make angles of 45° to the canal. Each mule is pulling on its rope with a force of 1.2 kN. How much work is done on the barge by both of these mules together as they pull the barge 154 m along the canal?

Homework Equations

W = F(mule)*x*cos(theta)

The Attempt at a Solution

I found the work done by one mule, but am not sure if it's correct:

W = F(mule)*x*cos(theta)
W = (1200 N)*(154 m)*cos(45)
W = 1.31 x 10^5 J

If it is correct, how do I find how much work is done by both mules?

yes, it is corect. Work is a scalar quantity, so total work obeys the usual rules of addition or subtraction.