A child pulls a wagon by the handle along a flat sidewalk.

[SilentWind12]

Homework Statement

A child pulls a trolley by the handle along a flat sidewalk. She exerts a force of 80.0 N at an angle of 30.0° above the horizontal while she moves the wagon 12 m forward. The force of friction on the trolley is 34 N.

Homework Equations

(a) Calculate the mechanical work done by the child on the trolley.
(b) Calculate the total work done on the trolley

The Attempt at a Solution

W=F(cos)
80 cos(30)[/B]
W=Fcosdeltad
W=80 N(cos30)(12)
=148J

b)Idk how to do it.

 

[haruspex]

W=80 N(cos30)(12)
=148J

Try that last step again, taking note that it is 30 DEGREES.
For b), what else is doing work on the trolley? How much work? Positive or negative?

 

[NascentOxygen]

(b) Calculate the total work done on the trolley

This could be worded: Calculate the net work done on the trolley.