Saved Bookmarks
| 1. |
Let `hatu, hatv, hatw` be three unit vectors such that `hatu+hatv+hatw=hata, hata.hatu=3/2, hata.hatv=7/4` & `|hata|=2`, thenA. `hatu hatv=3/4`B. `hatu.hatw=0`C. `hatu. Hatv=1/4`D. `hatu.hatw=-1/4` |
|
Answer» Correct Answer - A::D `hatu.hatv+hatu.hatw=1/2`…(ii) (taking dot product with `hatu,hatv` & `hata`) `hatu.hatv+hatv.hatw=3/4`………(iii) `hata.hatw=3/4`…………..(iv) Again taking dot product with `hatw` we get `hatu.hatw+hatv.hatw+|hatw|^(2)=hata.hatw` `hatu.hatw+hatu.hatw+1=3/4` `hatu.hatw+hatu.hatw=(-1)/4`............(v) on adding (ii),(iii),(v) `hatu.hatv+hatv.hatw+hatu.hatw=1/2` on substrating equation (ii) from (iv) `hatv.hatw=0` |
|