Question

force f is equal to 2i - 2j + K is applied to a particle is position vector is R is equal to i + J + K find the moment of force about origin if force is N and R is metres​

Answer 1

Answer:

     given,

             F=2i-2j+k

             R=i+j+k

     now,

              moment of force i.e

                                   τ = R X F

                                      =RFsinΘ

                                     =RFsin90          (taking Θ as 90 ,as nothing mentioned in question)

                                     =(i+j+k)(2i-2j+k)

                                     =$\left[\begin{array}{ccc}i&j&k\\1&1&1\\2&-2&1\\\end{array}\right]$

                                     =3i+j-4k