Question

what does this mean that newtons ist law is contained in newtons 2nd law of motion

Answer 1

because with the help of second law we can prove first law



second law says
f=ma
in absence of external force f=0
so a=0;as mass can't be zero.
so body at rest remain at rest or body in motion remain in motion

Answer 2

ᴀɴsᴡᴇʀ࿐

ɴᴇᴡᴛᴏɴ's ʟᴀᴡ ᴏғ ᴍᴏᴛɪᴏɴ:-

1sᴛ ʟᴀᴡ:-

ᴏʙᴊᴇᴄᴛ ɪɴ ᴍᴏᴛɪᴏɴ ᴛᴇɴᴅs ᴛᴏ sᴛᴀʏ ɪɴ ᴍᴏᴛɪᴏɴ ᴀɴᴅ ᴏʙᴊᴇᴄᴛ ᴀᴛ ʀᴇsᴛ ᴛᴇɴᴅs ᴛᴏ sᴛᴀʏ ᴀᴛ ʀᴇsᴛ ᴜɴʟᴇss ᴀᴄᴛᴇᴅ ᴜᴘᴏɴ ʙʏ ᴀɴ ᴜɴʙᴀʟᴀɴᴄᴇᴅ ғᴏʀᴄᴇ.

2ɴᴅ ʟᴀᴡ:-

ғᴏʀᴄᴇ ᴇǫᴜᴀʟ ᴍᴀss ᴛɪᴍᴇs ᴀᴄᴄᴇʟᴇʀᴀᴛɪᴏɴ(ғ= ᴍᴀ)

3ʀᴅ ʟᴀᴡ:-

ғᴏʀ ᴇᴠᴇʀʏ ᴀᴄᴛɪᴏɴ ᴛʜᴇʀᴇ ɪs ᴀɴ ᴇǫᴜᴀʟ ᴀɴᴅ ᴏᴘᴘᴏsɪᴛᴇ ʀᴇᴀᴄᴛɪᴏɴ.