A bird first towards east through a distance of 100 m, then heading towards north by a distance of 50 m, it flies vertical up through a distance of 20m. Find the distance of the position of the bird relative to its initial position.

Explanation

The final position `vecr` of the bird is followed by three successive displacements `vecs_(1),vecs_(2)` and `vecs_(3)` as shown in the fig where `vecs_(1)=100hati,vecs_(2)=50hatj` and `vecs_(3)=20hatk` as shown in the fig

Hence the position vector `vecr=vecs_(1)+vecs_(2)+vecs_(3)=100hati+50hatj+20hatk`
`|vecr|=113.6m`