The torque of the force `vecF=(2hati-3hatj+4hatk)N` acting at the point `vecr=(3hati+2hatj+3hatk)m` about the origin be

Options

A. `-17 hati +6hatj+13 hatk N-m`
B. `17hati-6hatj-13 hatk N-m`
C. `10 hati+8hatj-3hatk N-m`
D. `-8hati+10 hatj+3hatk N-m`

Answer

B

Explanation

`vec tau = vec r xx vec F =|{:(hati, hatj, hatk),(3,2,3),(2,-3,4):}|`
`=hati [2xx4-3(-3)] + hatj [3xx2-4xx3]+ hatk [(3xx-3)-2xx2]`
`vec tau =17 hati-6hatj-13 hatk N-m`