The composite material is composed of carbon fiber and epoxy resins. Now, density is an intensive unit. So, to approach this problem, let's assume there is 1 gram of composite material. Thus, mass carbon + mass epoxy = 1 g.
Volume of composite material = 1 g / 1.615 g/cm³ = 0.619 cm³
Volume of carbon fibers = x g / 1.74 g/cm³
Volume of epoxy resin = (1 - x) g / 1.21 g/cm³
a.) V of composite = V of carbon fibers + V of epoxy resin
0.619 = x/1.74 + (1-x)/1.21
Solve for x,
x = 0.824 g carbon fibers
1-x = 0.176 g epoxy resins
Vol % of carbon fibers = [(0.824/1.74) ÷ 0.619]*100 =<em> 76.5%</em>
b.) Weight % of epoxy = 0.176 g epoxy/1 g composite * 100 = <em>17.6%</em>
Weight % of carbon fibers = 0.824 g carbon/1 g composite * 100 = <em>82.4%</em>
Correct Answer is 1 i.e. Gamma rays—2 and radio waves—3
Reason:
1) In a hypernova, star<span> as similar to </span>nuclear fusion<span> converts lighter elements into heavy elements. If fusion is not capable of generating enough pressure to counteract gravity, star immediately collapses to form a </span>black hole<span>. During this process, energy will be released, along the axis of rotation to form </span>gamma-ray burst. Such gamma-ray burst was first detected using <span>Fermi Gamma-ray Space Telescope. Thus, gamma-ray is capable of providing information of gravity fields.
2) Radiowaves are capable of inducing transitions that requires less energies. These transition includes nuclear excitation and electron excitation (in rotational energy level). Depending upon the value to Jmax, it is possible to determine the temperature and </span><span>heat released by astronomical objects</span><span>
</span>
Answer: It's the anode broski (B)
Explanation: I'm taking the Chem summer course too broski, this was the correct answer. Cheers broski
Answer: Fe<em>(aq)</em>+S<em>(aq)</em>=FeS<em>(s)</em>
Explanation: The Sodium and Bromine are spectator ions because they don't react with anything, you can see this by writing the ionic equation like so:
1.) Molecular formula (given): FeBr2 (aq)+Na2S (aq)= FeS(s)+2NaBr(aq)
Each dissolved FeBr2 breaks up into one Fe with a charge of 2+ and two Br with a negative charge. This gives you:
Fe(aq)+ 2Br(aq)+Na2S(aq)=FeS(s)+2NaBr
2.) Now repeat what was shown with the other compounds in the given molecular formula, and pay attention to the states that each ion is in (solid, liquid, aqueous, gas) because this will give you the ionic equation, which from there you can get rid of any ions that don't change amount or state.
3.) Ionic formula: Fe(aq)+ <u>2Br(aq)</u>+<u>2 Na(aq)</u>+S (aq)=FeS(s)+<u>2 Na(aq)+2Br(aq)</u>
4.)When you've derived a total ionic equation (above), you'll find that some ions appear on both sides of the equation in equal numbers. For example, in this case two Na cations and two Br anions appear on both sides of the total ionic equation. What does this mean? It means these ions don't participate in the chemical reaction. They're present before and after the reaction. Nothing happens to them. So those are removed and you're left with the net ionic: Fe(aq)+S(aq)=FeS(s)
Hope this helps :)
