AP EAMCET2013PhysicsMathematics in Physics
The work done in moving an object from origin to a point whose position vector is r =3 i +2 j -5 k by a force F =2 i - j - k is
Options
- A1 unit
- B9 unit
- C13 unit
- D60 unit
Correct answer
B. 9 unit
Step-by-step solution
We know, work done W= F d Given, force, F =2 i - j - k , and position vector, d =3 i +2 j -5 k Using vector identify i i = j j = k k =1 Hence, W = F d =(2 i - j - k ) (3 i +2 j -5 k )=6-2+5=9 units