Question

A force F at an angle θ above the horizontal is used to pull a heavy suitcase of weight mg a distance d along a level floor at constant velocity. The coefficient of friction between the floor and the suitcase is μ. The work done by the frictional force is ________.(A) -Fd cos θ (B) - µ Fd cos θ (C) -µmgd (D) -µ mgd cos θ

Answer 1

Work done
`W=-\mu mgcos\Theta`

So option (d) will be correct option

Step-by-step explanation:

We have given that applied force is F

Angle above the horizontal is
`\Theta`

Coefficient of friction is
`\mu`

So frictional force will be equal to
`f=\mu mg`

Distance is given as d

Work done is equal to
`W=-\mu mgcos\Theta` ( Negative direction is due to frictional force as it is a opposing force )

So work done
`W=-\mu mgcos\Theta`

So option (d) will be correct option