The vector is rotated through an angle and doubled in magnitude, then it becomes . Then, the values of x are
2, 7
If a, b and c are three vectors, such that , , then a . b + b . c + c . a is equal to
0
- 7
7
1
Let u = , v = and w = . If is a unit vector such that = 0 and = 0, then is equal to
0
1
2
3
D.
3
A particle is acted upon by constant forces and which displace it from a point to the point . The work done in standard unit by the forces is given by
40
30
25
15