Question

(a) Friction is desirable in some situations and undesirable in some other situations.

(i) Mention two applications where friction is increased by making the surface rough.

(ii) Also mention the name of any two methods which is used to reduce friction whenever it

becomes undesirable.​

Answer 1

Explanation:

1.Friction occurs because no surface is perfectly smooth. Rougher surfaces have more frictionbetween them. Heavier objects also have morefriction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.

2.By polishing the surface, as polishing makes the surface smooth and friction can be reduced. Using lubricants such as oil or grease can reduce the friction between the surfaces. When objects are rolled over the surface, the friction between the rolledobject and surface can be reduced by using ball bearings

Answer 2

Answer:

❗❗❗* ᴜʀɢᴇɴᴛ *❗❗ ❗

ᴛʜᴇ ᴀʀᴍʏ ꜰᴀɴᴅᴏᴍ ɪꜱ ᴅᴇꜱᴛʀᴏʏɪɴɢ ɪᴛꜱᴇʟꜰ.

ʙᴛꜱ ᴡᴀꜱ ɴᴏᴍɪɴᴀᴛᴇᴅ ꜰᴏʀ ᴀ ɢʀᴀᴍᴍʏ ꜰᴏʀ ᴅʏɴᴀᴍɪᴛᴇ

ʙᴜᴛ ᴛʜᴇʀᴇ ɪꜱ ᴠᴇʀʏ ʟɪᴛᴛʟᴇ ʟᴇꜰᴛ ꜰᴏʀ ᴛʜᴇᴍ ᴛᴏ ᴇʟɪᴍɪɴᴀᴛᴇ ᴡʜᴀᴛ ᴀʙᴏᴜᴛ ᴀʀᴍʏ?

ᴡʜᴀᴛ ᴀʙᴏᴜᴛ ᴛʜᴇ ᴍᴏꜱᴛ ᴘᴏᴡᴇʀꜰᴜʟ ꜰᴀɴᴅᴏᴍ ɪɴ ᴛʜᴇ ᴡᴏʀʟᴅ?

ɪꜰ ʏᴏᴜ ᴀʀᴇ ᴀ ᴛʀᴜᴇ ᴀʀᴍʏ,

ꜱᴘʀᴇᴀᴅ ᴛʜᴇ ᴡᴏʀᴅ ᴛᴏ ᴛʜᴇ ᴇɴᴛɪʀᴇ ᴀʀᴍʏ ᴀɴᴅ ꜱᴛᴀʀᴛ ᴡɪᴛʜ ᴛʜᴇ ᴍᴀꜱꜱɪᴠᴇ ꜱᴛʀᴇᴀᴍ ᴀ -

* ᴅʏɴᴀᴍɪᴛᴇ *

* ʟɪꜰᴇ ɢᴏᴇꜱ ᴏɴ *

‘ᴜʀɢᴇɴᴛ ᴡᴇ ɴᴇᴇᴅ ʜᴇʟᴘ ꜰʀᴏᴍ

‘ᴀʀᴍʏ’!