Write a vector in the direction of vector `5 hat i- hat j+2 hat k` which has magnitude of 8 unit.

Explanation

` vec a=5 hat i- hat j+2 hat k` is,

`vec r=veca /|vec a|`

`= { 5 hat i- hat j+2 hat k}/sqrt{5^2+(-1)^2+2^2}`

`={ 5 hat i- hat j+2 hat k}/sqrt{30}`

`= 5/sqrt(30) hat i-1/sqrt30 hat j+2/sqrt30 hat k`

A vector in the direction of ` 5 hat i- hat j+2 hat k `
which has magnitude of 8 units, is

`=8vecr`

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