Question

The force vector is F=2i+6j+7k and body covers a displacement of 2m along y-axis the work done is.....?
A)√89×2j B)3i+6kj C)10j D)13j

Answer 1

Data Given. force
\[F = 2i + 6 j + 7k\]
and displacement
\[s = 2 j\]
Work done is given by dot product of force vector and displacement vector. So
\[W = F.s = (2i+6j+7k).(2j) = 4 i.j +12 j.j +14 k.j = 4\times0 +12\times1+14\times0\]
\[W = 12 J\]