Anhydrous $Na_2CO_3$ is also known as

If $\tan ^{-1} a+\tan ^{-1} b+\tan ^{-1} c=\pi$,then which of the following statements is true?

An atomic power nuclear reactor can deliver $300\, MW$. The energy released due to fission of each nucleus of a uranium atom ${U^{238}}$ is $170\, MeV$. The number of uranium atoms fissioned per hour will be

The maximum value of $Z=x+y$,subjected to $x+y \leq 10$,$5x+3y \geq 15$,$x \leq 6$,$x, y \geq 0$.

$A$ metal ball of mass $2 \ kg$ moving with a velocity of $36 \ km/h$ has a head-on collision with a stationary ball of mass $3 \ kg$. After the collision,if both balls move together,the loss in kinetic energy due to the collision is: (in $J$)

The path length of oscillation of a simple pendulum of length $1 \ m$ is $16 \ cm$. Its maximum velocity is $(g = \pi^2 \ m/s^2)$