Which of the following statement$(s)$ is are correct?
If the resultant of three forces is zero, then the vectors must be equal magnitude
If the resultant of four non-zero forces is zero, then the vectors must be coplanar
If the resultant of three non-zero vectors, is zero, then the vectors must be coplanar
All of these
The projection of a vector $\vec r\, = \,3\hat i\, + \,\hat j\, + \,2\hat k$ on the $xy$ plane has magnitude
Two forces $P + Q$ and $P -Q$ make angle $2 \alpha$ with each other and their resultant make $\theta$ angle with bisector of angle between them. Then :
A particle starting from the origin $(0,0)$ moves in a straight line in the $(x, y)$ plane. Its coordinates at a later time are $(\sqrt 3,3)$ . The path of the particle makes with the $x -$ axis an angle of ....... $^o$
The angles which a vector $\hat i + \hat j + \sqrt 2 \,\hat k$ makes with $X, Y$ and $Z$ axes respectively are