The correct option is D.
The model developed by Ptolemy has a lot of inconsistency and during the middle age additional explanation was offered for the claims made by the model. The model was very complicated because it was based on erroneous assumptions.
Copernicus model was simpler and some of his claims were correct.<span />
Answer:
the molecular formula for the gas is NO₂
Explanation:
since it contains
Nitrogen = n → 30.45%
Oxygen = o → 69.55%
and 30.45%+69.55% = 100% , then the gas only contains nitrogen and oxygen
Also we know that the proportion of oxygen over nitrogen is
proportion of oxygen over nitrogen = moles of oxygen / moles of nitrogen
since
moles = mass / molecular weight
then for a sample of 100 gr of the unknown gas
mass of oxygen = 69.55%*100 gr = 69.55 gr
mass of Nitrogen = 30.45%*100 gr = 30.45 gr
proportion of oxygen over nitrogen = (mass of oxygen/ molecular weight)/(mass of nitrogen / molecular weight of nitrogen ) = (69.55 gr/ 16 gr/mol) /( 30.45 gr /14 gr/mol) = 1.998 mol of O/ mol of N≈ 2 mol of O/ mol of N
therefore there are 2 atoms of oxygen per atom of nitrogen
thus the molecular formula for the gas is:
NO₂
Answer:
Explanation:
The form of Newton's 2nd Law that we use for this is:
F - f = ma where F is the Force pulling the mass down the ramp forward, f is the friction trying to keep it from moving forward, m is the mass and a is the acceleration (and our unknown).
We know mass and we can find f, but we don't have F. But we can solve for that by rewriting our main equation to reflect F:
That's everything we need.
w is weight: 6.0(9.8). Filling in:
6.0(9.8)sin20 - .15(6.0)(9.8) = 6.0a and
2.0 × 10¹ - 8.8 = 6.0a and
11 = 6.0a so
a = 1.8 m/s/s
