Answer:
The velocity of the photo electron is
.
Explanation:
Given that,
Supplied energy, 
Minimum energy of the electron to escape from the metal, 
We need to find the velocity of the photo electron. The energy supplied by the photon is equal to the sum of minimum escape energy and the kinetic energy of the escaping electron. So,

The formula of kinetic energy is given by :

So, the velocity of the photo electron is
.
Explanation:
The left side of the periodic table has elements that have less number of electrons in the valence shell.
These elements loose electrons easily.These elements appear as metals or metalloids in nature.These are hard solids.Their inter molecular forces are very strong.
The right side of the periodic table has elements that have more number of electrons in the valence shell.
These elements gain electrons easily.These elements appear as non metals most of which are gases.Their inter molecular forces are weak.
The momentum of the truck is given by:
p = mv
p = momentum, m = mass, v = velocity
There isn't too much work to do here; the truck is at rest, therefore its velocity is 0. This means the product of m and v is 0, giving the momentum as 0.