Q.

A small particle moves to position 5i^-2j^+k^ from its initial position 2i^+3j^-4k^ under the action of force 5i^+2j^+7k^N. The value of work done will be _________ J.           [2023]


Ans.

(40)

W=F(rf-ri)

     =(5i^+2j^+7k^)·[(5i^-2j^+k^)-(2i^+3j^-4k^)]

W=40 J