Search results
Results From The WOW.Com Content Network
If a comet with this speed fell to the Earth it would gain another 63 MJ/kg, yielding a total of 2655 MJ/kg with a speed of 72.9 km/s. Since the equator is moving at about 0.5 km/s, the impact speed has an upper limit of 73.4 km/s, giving an upper limit for the specific energy of a comet hitting the Earth of about 2690 MJ/kg.
Since the heat of combustion of these elements is known, the heating value can be calculated using Dulong's Formula: HHV [kJ/g]= 33.87m C + 122.3(m H - m O ÷ 8) + 9.4m S where m C , m H , m O , m N , and m S are the contents of carbon, hydrogen, oxygen, nitrogen, and sulfur on any (wet, dry or ash free) basis, respectively.
2 (736 J⋅K −1 ⋅kg −1) is greater than that of an hypothetical monatomic gas with the same molecular mass 28 (445 J⋅K −1 ⋅kg −1), by a factor of 5 / 3 . The vibrational and electronic degrees of freedom do not contribute significantly to the heat capacity in this case, due to the relatively large energy level gaps for both ...
Molecular spring approximate [citation needed] 1: battery, Lithium–Manganese [19] [20] 0.83-1.01: 1.98-2.09: battery, Sodium–Sulfur: 0.72 [21] 1.23 [citation needed] 85% [22] battery, Lithium-ion [23] [24] 0.46-0.72: 0.83-3.6 [25] 95% [26] battery, Sodium–Nickel Chloride, High Temperature: 0.56: battery, Zinc–manganese (alkaline), long ...
Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong–Petit limit of 25 J⋅mol ...
It is also an SI derived unit of molar thermodynamic energy defined as the energy equal to one joule in one mole of substance. [1] [2] For example, the Gibbs free energy of a compound in the area of thermochemistry is often quantified in units of kilojoules per mole (symbol: kJ·mol −1 or kJ/mol), with 1 kilojoule = 1000 joules. [3]
The kinetic energy of a 2 kg mass travelling at 1 m/s, or a 1 kg mass travelling at 1.41 m/s. The energy required to lift an apple up 1 m, assuming the apple has a mass of 101.97 g. The heat required to raise the temperature of 0.239 g of water from 0 °C to 1 °C. [15] The kinetic energy of a 50 kg human moving very slowly (0.2 m/s or 0.72 km/h).
Since the molar heat capacity of a substance is the specific heat c times the molar mass of the substance M/N its numerical value is generally smaller than that of the specific heat. Paraffin wax, for example, has a specific heat of about 2500 J⋅K −1 ⋅kg −1 but a molar heat capacity of about 600 J⋅K −1 ⋅mol −1.