When two objects are rubbed together, it creates a force of friction. We often find it difficult
to walk on smooth oily floor. Friction causes moving object to stop or even helps us to hold
objects properly. It is a very useful force but at the same time it also
becomes an evil.
a. What is the cause of friction ?
b. If an object is moving in east direction, in which direction does the force of friction act
on the body?
c. Give the factors on which force of friction depends.
d. Give two points to support the statement that “ friction is an evil”
Answers
Answer:
a. friction is evil when riding a slide with more irregularities
b. towards west
c. irregularities on the floor and object
d. When riding a slide if more friction then the person will not be able side down fast. When sliding an object if more friction then the box moves slowly and needs more force to overcome it.
Answer:
a. Friction is caused due to the interlockings of irregularities between two surfaces in contact.
b. The force of friction acts on the body from the west direction.
c. Force of friction depends upon:
(1) The nature of two surfaces in contact.
(2) The force pressing the two surfaces together.
d. Friction is an evil as:
(1) A lot of useful energy is wasted when effort is applied to overcome friction.
(2) Friction is also responsible for a lot of wear and tear in moving parts or objects.