Question icon
Grade 11Mechanics

find the work done by the force f and why change in kinetic energy is zero

Question image for find the work done by the force f and why change i
Profile image of kapil Mundra
8 Years agoGrade 11
Answers icon

3 Answers

Profile image of Sayani
8 Years ago
Without a suitable diagram it is difficult to identify which particular case this question deals with. a diagram is required.
 
Profile image of Sayani
8 Years ago
oh sorry i failed to notice the attachment. Is FLcos theta your answer? work done should most probably be this
Profile image of downey zer
8 Years ago
Since the process is gradual that means the object does not acquire any appreciable velocity int the process
Therefore change in KE of mass is equal to 0.
But gravity has done work on the object in the process which is =-mgl(1-cos(theta))
therefore the work done by the variable force is = +mgl(1-cos(theta)) for the total to be zero.