Answer:
we do not exceed that value, the force of having a value less than that calculated
Explanation:
Pressure is defined by
P = F / A
F = P A
F = 180 10⁶ A
for an exact calculation the area of the wire is needed
So that we do not exceed that value, the force of having a value less than that calculated
therefore the correct answer is "a smaller value"
If we neglect friction/air resistance, then the horizontal component
doesn't change, and the vertical component becomes (9.8 m/s downward)
greater each second thanks to gravity.
So, after 2 seconds, the horizontal component is still 40 m/s, and the
vertical component is (30 - 2·9.8) = 10.4 m/s upward.
Choice #1 says this.
That's false. Think about a stone or a baseball, during the first
several seconds after you tossed it straight up, before it reaches
its maximum height and starts to come down again.
There's no upward force on it during that time.
Also, after a roller coaster reaches the top of the FIRST hill, there's
no upward force on it for the whole rest of the ride, even though it
coasts up many more hills.
<span>Answer:
For Lewis theory, the most stable species will have a complete octet for as many atoms as possible. Construct Lewis dot structures for each species. You should see that CN+ cannot give a complete octet to the C atom unless a quadruple bond - unknown except in transition metals - is formed. CN will have an odd number of electrons, and is thus a free radical and unstable with respect to dimerization (it forms cyanogen). CN-, the familiar cyanide ion, gives both C and N a complete octet with a triple bond, and is thus the most stable.
Molecular orbital theory is a bit more complex. Nitrogen and carbon are close enough in electronegativity, so the orbitals from the C atom will mix with the same orbitals from the N atom. The molecular orbitals formed will be sigma2s, sigma*2s, pi2p, sigma2p, pi*2p, and sigma*2p. The * denotes an antibonding orbital; these are higher in energy, and electrons placed into these orbitals weaken the bonding between two atoms. CN+ will completely fill the sigma2s, sigma*2s, and pi2p orbitals. CN will add an electron in the bonding sigma2p orbital, and the atoms are thus more strongly bonded than in CN+. CN- fills the sigma2p orbital, and the addition of another bonding electron means that this species has the strongest bond of the three. I might have the names of some of the filled levels incorrect; the energy levels of the sigma2p and pi2p swap at some point. This concept is hard to explain without a picture; see the link.
Thus, both MO and Lewis theory predict CN- as the most stable species, a prediction that matches well with experimental data.</span>
C. easier to build than a refracting telescope
Big mirrors used in reflecting telescopes are easier and cheaper to make than big lenses which would cost more because of the quality of glass required to make refracting telescopes