To find the surface area of a single cube we first nees to take the cube root of 8cm3 which is 2.
Now we know that the length of each side is 2 and we can find the area of one side by doing 2x2 which is 4.
To find the total surface area of one cube we do 4 times 6 side giving us a total of 24cm2.
To find the total surface area of the 8 individual cubes, we multiply 24cm2 by 8 to give us a total of 192cm2.
Now to find the total surface area of the one large cube, we know that each side of one of the small cubes is 4cm2 and the large cube is set up so that there are two levels of four cubes right on top of each other. So, the total area of each side of the large cube is 4cm2 times 4 which gives us 16cm2.
Then we multiply 16cm2 by 6 sides to give us a total surface area of 96cm2.
The ratio of the surface area of the single large cube comapred to the total surface area of the single cubes is 96:192
We can further simplify this ratio:
96:192
48:96
24:48
12:24
6:12
3:6
1:2
Answer:
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
Explanation:
Given data
Φ = 5.32 eV
to find out
the longest wavelength
solution
we know that
hf = k(maximum) +Ф ...............1
here we consider k(maximum ) will be zero because photon wavelength max when low photon energy
so hf = 0
and hc/ λ = +Ф
so λ = hc/Ф ................2
now put value hc = 1240 ev nm and Φ = 5.32 eV
so hc = 1240 / 5.32
hc = 233 nm
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
The bimetallic strip in a fire alarm is made of two metals with different expansion rates bonded together to form one piece of metal. Typically, the low-expansion side is made of a nickel-iron alloy called Invar, while the high-expansion side is an alloy of copper or nickel. The strip is electrically energized with a low-voltage current. When the strip is heated by fire, the high-expansion side bends the strip toward an electrical contact. When the strip touches that contact, it completes a circuit that triggers the alarm to sound. The width of the gap between the contacts determines the temperature that will set off the alarm.
