On that list of choices, 'C' is the only "example" of a plane.
None of the choices "describes" a plane.
Answer:
About 133 db.
Explanation:
Sound Intensity Level in db (SIL db) is equal to 10log (base 10) times the ratio of the sound intensity at 200 watts (I) relative to the sound intensity of the reference sound intensity (I sub 0), which by default is equal to 10⁻¹² W/m² or 0 dB.
I = 200 w / 10 m^2 = 20 w per square meter
I sub 0 = 10^-12 w per square meter
SIL = 10log ( I / I sub o) = 20 / 10^-12 = 10log ( 20^12) = 10 ( 13.3 ) = 133 db
Hope I typed this part correctly. Hard to get it in without being able to do exponents, etc. :D
Answer:
The answer to your question is 784.8 J. None of your answer, did you forget some information?
Explanation:
Data
mass = 20 kg
distance = 4 m
work = ?
Formula
Work = force x distance
Force = mass x gravity
Process
1.- Calculate the weight of the block
Weight = 20 x 9.81
Weight = 196.2 N
2.- Calculate the work done
Work = 196.2 x 4
Work = 784.8 J
Answer:
D. the amount of chemical energy equals the amount of heat and light energy.
Explanation:
Given that the first law of thermodynamics affirmed that energy is neither created nor destroyed however, it can be transformed from one form to another. In other words, while, during the transformation of energy, no energy is lost, the input energy is also equal to output energy.
Hence, the chemical energy stored in the log is EQUAL to the heat and light energy produced by burning.
Answer:

Definition:
Half-life- The time taken for half of the radioactive isotopes to decay.
Explanation:
How does radioactive decay work? Radioactive decay is a process by which unstable nuclei become more stable through the emission of alpha or beta particles or gamma rays.
Since a half-life is the time taken for half of the isotopes to decay, we can simply divide the initial mass of 100 grams by 2; this gives us 50 grams.
1) Divide 100g by 2.
