What are the metal ions present in carnallite?

Two particles of masses $m_1$ and $m_2$ in projectile motion have velocities $\vec{v}_1$ and $\vec{v}_2$ respectively at time $t = 0$. They collide at time $t_0$. Their velocities become $\vec{v}_1'$ and $\vec{v}_2'$ at time $2t_0$ while still moving in air. The value of $|(m_1 \vec{v}_1' + m_2 \vec{v}_2') - (m_1 \vec{v}_1 + m_2 \vec{v}_2)|$ is

$A$ salt $MX$ has $K_{sp} = 4 \times 10^{-10}$. What value of $K_{sp}$ must another salt $MX_3$ have if the molar solubility of the two salts is to be identical?

If the imaginary part of $\frac{2z+1}{iz+1}$ is $-2$,then the locus of the point representing $z$ in the Argand plane is

The coordinates of the point $P$ on the curve $x=a(\theta+\sin \theta), y=a(1-\cos \theta)$,where the tangent is inclined at an angle $\frac{\pi}{4}$ to the $x$-axis,are

The product $(A)$ is: