Answer:
Renewable energy sources 1.Cost more then nonrenewable resources and 2.Are so far not as reliable as nonrenewable energy.
Explanation:
The answer is A.
Hydroelectric, which is usually generating electricity through use of a dam.
Solar, energy from the Sun.
Biomass, organic material formed from plant matter.
Answer:
Explanation:
The difference of electric potential between two points is given by the formula 
, where <em>d</em> is the distance between them and<em> E</em> the electric field in that region, assuming it's constant.
The electric field formula is 
, where <em>F </em>is the force experimented by a charge <em>q </em>placed in it.
Putting this together we have 
, so we need to obtain the electric force the charged ball is experimenting.
On the second drop, the ball takes more time to reach the ground, this means that the electric force is opposite to its weight <em>W</em>, giving a net force 
. On the first drop only <em>W</em> acts, while on the second drop is <em>N</em> that acts.
Using the equation for accelerated motion (departing from rest) 
, so we can get the accelerations for each drop (1 and 2) and relate them to the forces by writting:
These relate with the forces by Newton's 2nd Law:
Putting all together:
Which means:
And finally we substitute:
Which for our values means:
Correct answer choice is:
B. 50 percent
Explanation:
France Capitulates to Nazi Germany. On June 22, 1940, the French state approved a cease-fire with Nazi Germany just six weeks after the Nazis began their incursion of Western Europe.
Paris began preparing for combat in September 1939, when Nazi Germany overran Poland, but the combat appeared far beyond until May 10, 1940, when the Germans invaded France and immediately took the French troops. The French administration left Paris on June 10, and the Germans controlled the capital on June 14.
Answer: thickness h = 0.014cm
Question: In the manufacturing of computer chips, cylinders of silicon are cut into thin wafers that are 3.30 inches in diameter and have a mass of 1.50 g of silicon. How thick (mm) is each wafer if silicon has a density of 2.33 g/cm 3 ? (The volume of a cylinder is V=πr 2 h )
Explanation:
The volume of a cylinder is
Volume V = πr^2h ....1
The density of a material is
Density D = mass m / volume V
D = m/V ....2
Since m and D are given, we can make V the subject of formula.
V = m/D ....3
From equation 1, we need to derive the thickness h of the cylindrical silicon.
h = V/πr^2 .....4
Substituting equation 3 into 4
h = (m/D)/πr^2 .....5
Given.
mass m = 1.50g
density D = 2.33g/cm^3
radius r = diameter/2 = 3.00in/2 = 7.62/2 cm = 3.81cm
Substituting the given values into the equation
h = (1.5/2.33)/(π ×3.81^2)
thickness h = 0.014cm
