Which of the following are the three basic types of static stresses to which a material can be subjected (three correct answers)
1 answer:
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To compute the energy, Q, needed to melt a certain amount of ice, n, in moles, we have
where the latent heat of fusion for ice is equal to 6.009 kJ/mol.
Now, since we have a 20.0 lb ice, we must first convert its mass to grams. Thus mass = (20.0)(1000)(0.4536) = 9072 g.
To find the number of moles present, we must recall that the molar mass of water (ice) is equal to <span>1.00794(2) + </span><span>15.9994 </span>≈ 18.01 g/mol. Hence, we have
Now, to compute for the molar heat of fusion, Q,
Therefore, the amount of heat needed to melt the 20-lb bag of ice is equal to 3026.9 kJ.
Answer: 3026.9 kJ
where the latent heat of fusion for ice is equal to 6.009 kJ/mol.
Now, since we have a 20.0 lb ice, we must first convert its mass to grams. Thus mass = (20.0)(1000)(0.4536) = 9072 g.
To find the number of moles present, we must recall that the molar mass of water (ice) is equal to <span>1.00794(2) + </span><span>15.9994 </span>≈ 18.01 g/mol. Hence, we have
Now, to compute for the molar heat of fusion, Q,
Therefore, the amount of heat needed to melt the 20-lb bag of ice is equal to 3026.9 kJ.
Answer: 3026.9 kJ
Answer:
The time required to melt the frost is 3.25 hours.
Explanation:
The time required to melt the frost dependes on the latent heat of the frost and the amount of heat it is transfered by convection to the air .
The heat transferred per unit area can be expressed as:
being hc the convective heat transfer coefficient (2 Wm^-2K^-1) and ΔT the difference of temperature (20-0=20 °C or K).
If we take 1 m^2 of ice, with 2 mm of thickness, we have this volume
The mass of the frost can be estimated as
Then, the amount of heat needed to melt this surface (1 m²) of frost is
The time needed to melt the frost can be calculated as