The coefficient of expansion is 13 * 10^-6 m per meter length.per oK
The temperature difference = 42 - - 8 = 50 oC
delta T = (42 + 273) - (-8 + 273) = 50 oK
delta L = L * 13* 10^6 m/oK
oK = 50 oK delta L = 19.5 cm = 19.5 cm [1m / 100 cm] = 0.195m
So we need to find the length and it is computed by:
0.195= L * 13 * 10^-6 * 50 L = 0.195 / (13*10^-6*50) L = 300 m
Answer:
D. Malleable
Explanation:
Gold is metallic, with a yellow colour when in a mass, but when finely divided it may be black, ruby, or purple. It is the most malleable and ductile metal; 1 ounce (28 g) of gold can be beaten out to 300 square feet. It is a soft metal and is usually alloyed to give it more strength.
Answer: you have loved ones who help you get through it and help answer the questions they know.
Part a
Answer: ![3.64\times10^{16}](https://tex.z-dn.net/?f=3.64%5Ctimes10%5E%7B16%7D)
For the arrangement considered in part a, all the atoms are aligned side by side along the side of the square surface.
Along one side of the square, the number of atoms that could fit ![=\frac {length\hspace{1mm}of\hspace{1mm}side}{diameter\hspace{1mm}of\hspace{1mm}atom}=\frac{9.5\times10^{-2}m}{4.95\times10^{-10}m}=1.91\times10^8 atoms](https://tex.z-dn.net/?f=%3D%5Cfrac%20%7Blength%5Chspace%7B1mm%7Dof%5Chspace%7B1mm%7Dside%7D%7Bdiameter%5Chspace%7B1mm%7Dof%5Chspace%7B1mm%7Datom%7D%3D%5Cfrac%7B9.5%5Ctimes10%5E%7B-2%7Dm%7D%7B4.95%5Ctimes10%5E%7B-10%7Dm%7D%3D1.91%5Ctimes10%5E8%20atoms)
This is along one side. On the entire surface:
Number of atoms ![= (1.91\times10^8 )^2=3.64\times10^{16} atoms](https://tex.z-dn.net/?f=%3D%20%281.91%5Ctimes10%5E8%20%29%5E2%3D3.64%5Ctimes10%5E%7B16%7D%20atoms)
Part b
Answer: ![4.23\times10^{16}](https://tex.z-dn.net/?f=4.23%5Ctimes10%5E%7B16%7D)
consider the attached figure below:
The next layer of atoms are filled in the depressions of the first layer. The vertical distance between the two atoms would change. Consider an equilateral triangle drawn by joining the centers of the three atoms.
The atoms along the horizontal side would be aligned side by side; same as above ![=1.91\times10^8 atoms](https://tex.z-dn.net/?f=%3D1.91%5Ctimes10%5E8%20atoms)
The number of atoms along vertical side would vary. vertical distance between two atoms can be calculate using equilateral triangle as shown below.
an equilateral triangle has all the angles ![= 60^o](https://tex.z-dn.net/?f=%3D%2060%5Eo)
Let the vertical distance be y.
Then, ![y = 2r sin60^o](https://tex.z-dn.net/?f=y%20%3D%202r%20sin60%5Eo)
where r is the radius of each atom. ![2r= 4.95\times10^{-10} m](https://tex.z-dn.net/?f=2r%3D%204.95%5Ctimes10%5E%7B-10%7D%20m)
![y=4.95\times10^{-10} m\times sin60^o=4.28\times10^{-10} m](https://tex.z-dn.net/?f=y%3D4.95%5Ctimes10%5E%7B-10%7D%20m%5Ctimes%20sin60%5Eo%3D4.28%5Ctimes10%5E%7B-10%7D%20m)
The number of atoms along the vertical side ![= \frac{9.5\times10^{-2}m}{4.28\times10^{-10}m}=2.21\times10^8 atoms](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7B9.5%5Ctimes10%5E%7B-2%7Dm%7D%7B4.28%5Ctimes10%5E%7B-10%7Dm%7D%3D2.21%5Ctimes10%5E8%20atoms)
Total number of atoms in this kind of arrangement ![= 1.91\times10^8\times2.21\times10^8=4.23\times10^{16} atoms](https://tex.z-dn.net/?f=%20%3D%201.91%5Ctimes10%5E8%5Ctimes2.21%5Ctimes10%5E8%3D4.23%5Ctimes10%5E%7B16%7D%20atoms)
Answer:
Q = 47443 J
Explanation:
Mas of the water is given as
![m = 25 lbs](https://tex.z-dn.net/?f=m%20%3D%2025%20lbs)
1 lb = 454 g
so we have
![m = 25 \times 454](https://tex.z-dn.net/?f=m%20%3D%2025%20%5Ctimes%20454)
![m = 11.35 kg](https://tex.z-dn.net/?f=m%20%3D%2011.35%20kg%20)
specific heat capacity of the water is given as
![s = 1 cal/g C](https://tex.z-dn.net/?f=s%20%3D%201%20cal%2Fg%20C)
![s = 1000\times 4.18 J/kg C](https://tex.z-dn.net/?f=s%20%3D%201000%5Ctimes%204.18%20J%2Fkg%20C)
![s = 4180 J/kg C](https://tex.z-dn.net/?f=s%20%3D%204180%20J%2Fkg%20C)
now heat required is given as
![Q = 11.35 (4180) (1)](https://tex.z-dn.net/?f=Q%20%3D%2011.35%20%284180%29%20%281%29)
![Q = 47443 J](https://tex.z-dn.net/?f=Q%20%3D%2047443%20J)