Answer:
B. over the symbol.
Explanation:
vectors are represented with a symbol carrying an arrow head with also indicates direction
Input work = 9.63×10³ J.
Output work = 3.0×10³ J
By definition,
Efficiency = (Output work)/(Input work)
= (3.0×10³)/(9.63×10³)
= 0.31 = 31%
Answer: 31%
The rays of light coming from the Sun are parallel to each other, so when they are reflected by the concave piece of glass (which acts as a concave mirror) they converge into the focus of the mirror, which is

The radius of curvature of a concave mirror is twice its focal length, so in this case it is:
Answer:
A
Explanation:
The greatest concentration of atomic mass is in the nucleus because it is made up of protons and neutrons. The electrons surrounding the nucleus don't have as much mass as protons or neutrons.
Hopefully this helps...
Answer:
atomic number
Explanation:
the number of protons in an atom is called its "atomic number"