8.2 CHAPTER 8. WORK, ENERGY AND POWER
Example 3: Calculating Work Done III
QUESTIONCalculate the work done on a box, if it is pulled 5 m along the ground by
applying a force of F=10 N at an angle of 60 ◦to the horizontal.60 ◦
F
SOLUTIONStep 1 : Analyse the question todetermine what information is provided- The force applied is F=10 N
- The distance moved is s=5 m along the ground
- The angle between theapplied force and the motion is
60 ◦
These quantities are inthe correct units so wedo not need to
perform any unit conversions.Step 2 : Analyse the question todetermine what is beingasked- We are asked to find the work done on the box.
Step 3 : Calculate the component of the applied force in the direction of
motionSince the force and the motion are not in the samedirection,
we must first calculate the component of the force in the direction
of the motion.60 ◦
F
F||
F�
From the force diagramwe see that the component of the