Question

Hii friends

How is friction sometimes desirable???

Answer 1

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✮✭ӇЄƦЄ ƖƧ ƳƠƲƦ ƛƝƧƜЄƦ✭✮
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Yᴇꜱ, ɪᴛ ɪꜱ ᴅᴇꜱɪʀᴀʙʟᴇ ᴛᴏ ꜱᴏᴍᴇ ᴇxᴛᴇɴᴛ.

➧ Exᴀᴍᴘʟᴇꜱ:-
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[1] Aᴇʀᴏᴘʟᴀɴᴇꜱ ᴄᴀɴ'ᴛ ғʟʏ ᴡɪᴛʜᴏᴜᴛ ᴍᴏᴠɪɴɢ ᴏɴ ᴛʜᴇ ɢʀᴏᴜɴᴅ (Fʀɪᴄᴛɪᴏɴᴀʟ Fᴏʀᴄᴇ).

[2] ꜱʜɪᴘ ᴄᴀɴɴᴏᴛ ᴍᴏᴠᴇ ᴡɪᴛʜᴏᴜᴛ ғʀɪᴄᴛɪᴏɴ.

[3] Fᴏʀ ᴇʀᴀꜱɪɴɢ ᴀ ᴍɪꜱᴛᴀᴋᴇ, ᴛʜᴇ ʀᴜʙʙᴇʀ ʜᴀꜱ ᴛᴏ ꜱʜᴏᴡ ғʀɪᴄᴛɪᴏɴ ᴡɪᴛʜ ᴛʜᴇ ᴘᴀᴘᴇʀ.

➠ Bᴜᴛ ᴅᴜᴇ ᴛᴏ ғʀɪᴄᴛɪᴏɴ, ᴛʜᴇʀᴇ ɪꜱ ᴀ ʜᴜɢᴇ ᴀᴍᴏᴜɴᴛ ᴏғ ᴇɴᴇʀɢʏ ɪꜱ ᴡᴀꜱᴛᴇᴅ. Oɴᴇ ᴡᴀʏ ᴛᴏ ᴅɪꜱᴄʀɪᴍɪɴᴀᴛᴇ ɪᴛ ɪꜱ:

➠ Pᴇᴏᴘʟᴇ ᴄᴀɴ ɢᴇᴛ ɪɴᴊᴜʀᴇᴅ ᴛʜᴇᴍꜱᴇʟᴠᴇꜱ, ɪғ ᴛʜᴇʏ ʀᴜʙ ᴛʜᴇɪʀ ʜᴀɴᴅꜱ ʜᴀʀᴅ ᴏɴ ғʟᴏᴏʀꜱ ᴏʀ ꜱʜᴀʀᴘ ɪᴛᴇᴍꜱ.

Answer 2

Friction is of utmost importance in some cases.

(1) It is the frictional force between the ground and our feet/shoes which help us to move forward. Without friction, we would slip down every now and then (just as walking on ice).

(2) Vehicle's brakes work on friction. Without friction between the brakes and the tyres, we wouldn't be able to stop our vehicles once started.

(3) We are able to write because of the presence of friction between pen and paper. Without friction, it would be same as writing on a glass piece.

(4) We couldn't even light a matchstick without friction.

(5) Air also has frictional force and since friction produces heat, this helps in burning of the meteoroids which strike our planet every now and then. Without friction, our planet could have been like moon where meteor hits are very common.

However, friction has many negative points also like it produces heat energy and this energy is wasted. Many machines don't work efficiently due to friction within their moving parts.

Hence, friction is desirable as well as undesirable at times. That is the reason it is also called "A necessary evil".

Hope this answer helps you. :-)