Answer:
Density is defined as:
Density = Mass/Volume
Now, density is an intensive property, this means that if you have 10 grams of a given material or 1000 grams of the same material, in both cases you will find the same density.
Then a roll of 50 pennies has the same density that a single penny.
The measures of a single penny are:
Mass = 2.5 g
Thickness = 1.52 mm
Radius = 9.525 mm
The coin is a cylinder, and the volume of a cylinder is:
V = pi*r^2*h
where:
pi = 3.14
r = radius = 9.525mm
h = thikness = 1.52mm
The volume is:
V = 3.14*(9.525mm)^2*1.52mm = 433.015 mm^3
The density will be:
D = 2.5g/433.015mm^3 = 0.00577 g/mm^3
Fill in the fraction: 3,600/90 = 40; turn it into a unit fraction.
40 mi/min
Answer: It is both B and D
Select all that apply.
At night, thermal energy moves _____.
from space to the atmosphere
from the land to the atmosphere
from the atmosphere to the land
from the atmosphere to space
Darwin's atomic theory which states that atoms do not emit or absorb energy so far as they remain in allowable orbits or ground states.It also states that a spectra is produced when an electron moves to a lower energy level thereby releasing energy.
Answer:
90.78 rev/min
Explanation:
In first place, we have to do the force balance to determine the minimum angular speed required to avoid slipping. The forces acting here are friction and the force due to circular movement, that is centripetal force. Then, we have:
μmg=mRω^2
ω=
Then, replacing the given values in the expression we have the following result:
ω=1.51 rev/s*60s=90.78 rev/min
