Question

A force f=(i+2j-k) N displace a body S(i+j-2k) m in 10 s what is power developed

Answer 1

P=(f.s)/t

{ (i+2j-k).(i+j-2k)}/10[rule of multiplication of dot product isi.i=1,j.j=1,k.k=1]

(1+2+2)/10

=5/10joule

=1/2joule power

.5joule power developed