A force `hat(F)=(hat(i)+2hat(j)-hat(k))N` moves a particle along a vector `hat(s)=(4hat(i)+hat(j)+7hat(k))` metre. What is the work done?

Explanation

Here, `hat(F)=(hat(i)+2hat(j)-hat(k))N` and `hat(s)=(4hat(i)+hat(j)+7hat(k))` metre, W=?
`W=hat(F).hat(s)=(hat(i)+2hat(j)-hat(k))=4(hat(i).hat(i)+2(hat(j).hat(j))-(hat(k).hat(k))=4+2-7=-1J`