data entry - Physics

Which science presents the changes in the internal and external structure of plants from the perspective of evolution and phylogeny?

Anhydrous $Na_2CO_3$ is also known as

$A$ circular disc of radius $R$ is removed from a bigger circular disc of radius $2R$ such that the circumferences of the discs touch. The centre of mass of the new disc is at a distance $\alpha R$ from the centre of the bigger disc. The value of $\alpha$ is

Which one of the following gases can deplete the ozone layer in the upper atmosphere?

The sum of the magnitudes of two forces acting at a point is $16 ~N$. If their resultant is normal to the smaller force and has a magnitude of $8 ~N$,then the forces are: