Give examples to show that friction is both a friend and a foe.
Answers
(i) Friction allows us to grip and catch different objects.
(ii) It helps us to walk comfortably on the surface.
(iii) It helps to minimise the speed or to stop the moving objects.
(iv) It helps us to write on paper or blackboard.
(v) The things do not move from their places due to friction.
(i) Friction causes wear and tear in objects.
(ii) It causes damage the parts of machines.
(iii) The machines or tools require regular maintenance due to which a lot of money is wasted.
(iv)It reduces the speed of moving objects so more force is required.
(v)It does not allow the free movement of objects.
Answer:
Friction as a friend:
It allows us to grip and catch any object.
It helps us to walk comfortably on the floor.
It helps to minimise the speed or to stop any moving object.
It helps us to write.
Friction as a foe:
It causes wear and tears in objects.
It causes damage to the parts of machines and tools which further require money to get them repaired.
It reduces the speed of moving objects, so more force is required.
It produces hurdles in moving any object freely.