0

The point of contact is being displaced along the surface. This would imply that some work is being done on the surface by friction. But there is no work done by friction on the ground. Please provide a detailed explanation.Body moving on a rough surface (May or may not be pure rolling)

StoneZoo
  • 17
  • 1
    "The point of contact is being displaced along the surface." Actually it isn't. The point of contact is momentarily stationary (I'm assuming rolling without slipping). – Steeven Jan 12 '21 at 15:54
  • But what if the ball is slipping on the surface? Would work done by friction still be zero? – StoneZoo Jan 12 '21 at 16:07
  • If not slipping then we have static friction. Static friction does no work. If slipping then we have kinetic friction. Kinetic friction does work like any other force that acts over a distance. – Steeven Jan 12 '21 at 16:15
  • If you rub the ground it would heat up. So work is done at the ground. This is exactly the same situation. – JAlex Jan 12 '21 at 16:20

1 Answers1

1

See my post here: Where does a torque-invoking force belong in work energy theorem? (instead of tension, think friction).

Essentially, there is work done while translating and work done due to the rotation. These works cancel.

user256872
  • 6,601
  • 2
  • 12
  • 33