Question

ustify the statement: ‘Friction is a necessary evil’. b) Identify the objects that increases and decreases friction from the given picture.​

Answer 1

• Friction is called a necessary evil because it is necessary and useful for many things in our day-to-day life. It is also called evil because it damages or disturbs many processes. Friction is necessary for walking, lifting, and writing. On the other hand, Friction is harmful in some manufacturing processes. It produces heat due to friction which results in the loss of energy, wear and tear of machinery parts, etc.
• In the given picture, Tyre increases friction while moving on the round which is beneficial.

• The Shoe increases the friction which helps in walking.
• The Oil decreases the friction. Oiling is used to decrease the friction in the machinery parts.
• Ball Bearing decreases friction as it rolls.