The frequency of the waves increases as you go from left to right on the El. spectrum / The length of the waves decreases as you go from left to the right on the El. spectrum - both of them are correct use the one you prefer more
P.S. most textbooks should show that radiowaves are on the left side and UV or gamma rays on the right - if it's opposite in your one then just replace the second word with their appropriate antonyms.
A regular pentagon may be divided into 5 congruent triangles.
If the side of the pentagon is 6 feet, each base of the triangles will be 6 feet.
If the distance from the center to a vertex is 6 feet, all the sides of the triangles will 6 feet.
So there are 5 congruent, equilateral triangles each with side equal to 6 feet.
The area one of those triangles is calculateb by:
base * height / 2
height ^2 = (side length) ^2 - (side length /2)^2 = 6^2 - 3^2 = 36 - 9 = 27
=> height = √(27) ≈ 5.2 feet
And, using area = base * height / 2 ,
area of a triangle = 6 feet * 5.2 feet / 2 = 15.6 feet^2
And the area of the entire pentagon equals 5 triangles ≈ 5 * 15.6 feet^2 = 78 feet^2
Answer: 78 feet^2
Strategy: with the measures you can determine the volume of the plate of aluminum. Then you can use the density of aluminum to calculate the mass.
With the mass of aluminum and its atomic mass you can find the number of moles and thereafter the number of atoms.
Finally divide the cost by the number of atoms to find the cost of one single atom.
Let's do it.
Volume of aluminum plate, V: 0.0112 in* 4.83 in* 2.60 in * [2.54 cm/in]^3 = 2.305 cm^3
Density of aluminum (from Wikipedia), d = 2.70 g/cm^3
mass, m = d*V = 2.305 cm^3 * 2.70 g/ cm^3 = 6.22 g
Atomic mass of aluminum (from Wikipedia), am = 27 g / mol
Number of moles, n = m/am = 6.22 g / 27 g / mol = 0.23 mol
Number of atoms = n*Avogadro constant = 0.23 mol * 6.022 * 10^23 atoms/mol = 1.39*10^23
Cost per atom = cost of the can / number of atoms =$ 0.05 /1.39*10^23 atoms = 3.60 * 10^ - 25 $/atom
For average speed, we divide the total distance covered by the total time taken.
After doing that, you will see that Jane has the lowest average speed.
