A snake slithers in a complete circle of radius 2.71 m. The coefficient of friction between the ground and the snake is 0.25

coefficient-friction

#1

A snake slithers in a complete circle of radius 2.71 m. The coefficient of friction between the ground and the snake is 0.25, and the snake’s weight is 69.0 N. How much work does the snake do against friction with the ground?

Answer:

Work done is generally equal to force times displacement. But this is only for conservative forces. For a non-conservative force, things are different.
In case of friction, the work done against it is force times the distance travelled as always the friction force opposes the motion (i.e. acts in opposite direction to it)
So
image

the work done will be = kWd
= (0.25)(69.0)(2pi2.71)
= 293.57 Joules