A plane is revolving around the earth with a speed of $100\, km/hr $ at a constant height from the surface of earth. The change in the velocity as it travels half circle is.........$km/hr$

and direction of the vectors $\hat{ i }+\hat{ j }$, and $\hat{ i }-\hat{ j }$ ? What are the components of a vector $A =2 \hat{ i }+3 \hat{ j }$ along the directions of $\hat{ i }+\hat{ j }$ and $\hat{ i }-\hat{ j } ?$

An observer moves with a constant speed along the line joining two stationary objects. He will observe that the two objects

A body starts from rest from the origin with an acceleration of $6 \;m / s^2$ along the $x$-axis and $8\; m / s^2$ along the $y$-axis. Its distance from the origin after $4\; seconds$ will be

$Assertion$ : If a body is thrown upwards, the distance covered by it in the last second of upward motion is about $5\, m$ irrespective of its initial speed
$Reason$ : The distance covered in the last second of upward motion is equal to that covered in the first second of downward motion when the particle is dropped.

The figure shows the velocity $(v)$ of a particle plotted against time $(t)$