wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A body of mass m was slowly hauled up the hill as shown in fig. 9.18 by a force F which at each point was directed along a tangent to the trajectory. Find the work performed by this force, if the height of the hill is h, the length of its base is l and the coefficient of friction is μ.
1084272_b289a9b668974a358c0bfd24c3b20446.png

Open in App
Solution

We know that friction force is f=μN=μmgcosθ where θ is inclination at that particular instant

Hence, work done against friction in moving distance dL along the incline is dWf=μmgcosθdL=μmgdx (dx=dLcosθ)

Hence, total work done against friction Wf=μmgl where l= total horizontal distance

Work done against gravity is Wg=mgh

Hence total work done is W=Wf+Wg

W=(μl+h)mg

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Mechanical Advantage in Lever_TACKLE
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon