Answer:
50km
Explanation:
70km - 20km = 50 kilometers
Heat_1: Get the ice to 0 degrees
Convert 7 kg to grams
7 kg [1000 grams / 1 kg] = 7000 grams
Heat needed to get the the ice from - 9 to 0
deltat = 0 - -9 = 9 degrees
m = 7000 grams
c = 2.1 joules/gram
Heat_1 = m*c*deltat
Heat_1 = 7000 * 2.1 * 9
Heat_1 = 132,300 joules
Heat_2: Melt the ice.
There is no temperature change. The formula is 333 j/gram
Formula: H = mass * constant
H = 7000 g * 333 J / gram
H = 2331000 joules
Heat_3: Total amount of Joules needed.
2331000 + 132300 = 2 463 300 joules
Convert to Megajoules
2 463 300 joules * 1 megajoule / 1000000 = 2.63 megajoules.
Answer
A. molecules
Explanation
When atoms or elements combine, they are called molecules. When molecules combine they form compounds.
Answer:
The degree of compactness of a substance
<u>Given:</u>
Frequency (ν) = 319 THz
<u>To determine:</u>
The wavelength corresponding to the given frequency
<u>Explanation:</u>
Wavelength (λ) and Frequency(ν) are related as:
λ = c/ν
where c = speed of light = 3*10⁸ m/s
Now:
SI unit of frequency is Hertz (Hz) also expressed as cycles per second
i.e 1 Hz = 1 s⁻¹
1 Terahertz (THz) = 10¹² Hz
therefore the given frequency ν = 319 *10¹² s⁻¹
λ = 3 * 10⁸ ms⁻¹/319 *10¹² s⁻¹ = 940 * 10⁻⁹ m
since 1 nanometer (nm) = 10⁻⁹ m
The wavelength is λ = 940 nm
Ans: The infrared wavelength = 940 nm
