A bus is moving on a straight road towards north with a uniform speed of $50\; km / hour$ then it turns left through $90^{\circ} .$ If the speed remains unchanged after turning, the increase in the velocity of bus in the turning process is
$50 \;km / hr$ along west
$0$
$70.7 \;km / hr$ along south-west direction
$70.7\; km / hr$ along north-west direction
If the angle between $\hat a$ and $\hat b$ is $60^o$, then which of the following vector $(s)$ have magnitude one
$(A)$ $\frac{\hat a + \hat b}{\sqrt 3}$ $(B)$ $\hat a + \widehat b$ $(C)$ $\hat a$ $(D)$ $\hat b$
The resultant of $\vec A$ and $\vec B$ makes an angle $\alpha $ with $\vec A$ and $\beta $ with $\vec B$,
How many minimum number of coplanar vectors having different magnitudes can be added to give zero resultant
Two forces $P$ and $Q$, of magnitude $2F$ and $3F$, respectively, are at an angle $\theta $ with each other. If the force $Q$ is doubled, then their resultant also gets doubled. Then, the angle $\theta $ is ....... $^o$