Actually, that does not happen until the protostar becomes a star when nuclear ignition starts and is maintained. It takes awhile for new star to go through its T-Tauri stage and settle down on the main sequence.
<span>A STAR does not reach hydrostatic equilibrium until it on the main sequence. Otherwise, it would remain a brown dwarf with not enough mass to to maintain nuclear fusion for more than 3,000 to 10,00 years. </span>
Answer:
t = 7.58 * 10¹⁹ seconds
Explanation:
First order rate constant is given as,
k = (2.303
/t) log [A₀]
/[Aₙ]
where [A₀] is the initial concentraion of the reactant; [Aₙ] is the concentration of the reactant at time, <em>t</em>
[A₀] = 615 calories;
[Aₙ] = 615 - 480 = 135 calories
k = 2.00 * 10⁻²⁰ sec⁻¹
substituting the values in the equation of the rate constant;
2.00 * 10⁻²⁰ sec⁻¹ = (2.303/t) log (615/135)
(2.00 * 10⁻²⁰ sec⁻¹) / log (615/135) = (2.303/t)
t = 2.303 / 3.037 * 10⁻²⁰
t = 7.58 * 10¹⁹ seconds
Answer: Inclined plane, simple machine consisting of a sloping surface, used for raising heavy bodies. The force required to move an object up the incline is less than the weight being raised, discounting friction. The steeper the slope, or incline, the more nearly the required force approaches the actual weight.
Explanation:
Answer:
In the 1H NMR spectrum of ethanol three different signals are observed, this is due to the existence of 3 types of hydrogens with different chemical environment. Hydrogens A (3.57 ppm) are more screened than C (1.10 ppm) due to the presence of oxygen (electonegative atom that removes electron density). The chemical environment of hydrogen B (4.78 ppm), attached directly to oxygen, is also different by resonating at a frequency different from the previous ones.
The hydroxylic hydrogen produces a singlet, the pair of carbon hydrogens one give rise to a quadruplet and the three hydrogens of carbon two produce a triplet.
Explanation:
