Answer:
Sodium-vapour lights
Explanation:
Sodium-vapour lights are lights that are a type of gas discharge lamp that uses sodium in a high energy state to produce light,sodium discharge lamps are one of the brightest form of lighting used in motor parks and streets. There are basically two types of sodium-vapour lights, they include the low pressure sodium-vapour lights and the high pressure sodium-vapour lights.
Answer:
A
Explanation:
Givens
d = 100 meters plus the depth of the well
d = 100 + x where x is the depth of the well.
vi = 0 m/s The object is dropped. It was not thrown.
t = 5 seconds
a = 9.81 m/s^2
formula
d = vi*t + 1/2 a t^2
solution
100 + x = 0 + 1/2 * 9.81 * 5^2
100 + x = 122.625 Subtract 100 from both sides
x = 122.625 - 100
x = 22.6 m
The well is 22.6 meters deep.
Answer;
D. The group number is equal to the number of valence electrons.
Explanation;
-The valence electrons are the electrons in the outer shell of an atom. The valence electrons are the ones involved in forming bonds to adjacent atoms. Therefore, the number of valence electrons is important for determining the number of bonds an atom will form, the number of unpaired electrons, and an atom’s formal charge.
-For neutral atoms, the number of valence electrons is equal to the atom’s main group number.
Number of valence electrons = main group number (neutral atoms)
-The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.
Answer:
gravity is the invisible force that attracts us the the earth\
1.normal force 2.frictional force 3. spring forces
flowing electrons produce a magnetic field
unbalanced forces are not equal they always cause changes in the moving object like the direction . balanced forces are equal and cause no changes
The SI system, also called the metric system, is used around the world. There are seven basic units in the SI system the meter kilogram second (s), kelvin the ampere , the mole and the candela.
