Convex lenses are thicker at the centers than the edges, they are known as the converging lenses. Rays of light that pass through the lens are brought closer together (they converge). When rays of light that are parallel pass through a convex lens they are refracted, the refracted rays converge at one point called the principal focus.
The conversion factor you use is 100 cm = 1 m.
You can divide 20 by 100 to get the answer.
20 cm/100 cm =.2 m
Hope this helped!
Answer: 
Explanation:
The de Broglie wavelength 
is given by the following formula:
(1)
Where:
is the Planck constant
is the momentum of the atom, which is given by:
(2)
Where:
is the mass of the electron
is the velocity of the electron
This means equation (2) can be written as:
(3)
Substituting (3) in (1):
(4)
Now, we only have to find :
>>> This is the de Broglie wavelength of the electron
Answer:
1. Convection (Moving Water)
2. Radiation (Sunlight)
3. Conduction (Direct Contact)
4. Convection or Radiation (Most Likely Convection) (Moving Air/Sunlight)
5. Convection (Moving Air)
6. Radiation (Feeling Heat)
Explanation:
See Above
