physics problem ?

Question

The lowest temperature measured on the surface of a planetary body in the solar system is that of Triton, The largest of Neptunes moons. The surface temperature on this distant moon can reach a low of -235 C. suppose an astronaut brings a water bottle containing .5 kg of water to Triton. The water temperature decreases until the water freezes, then the temperature of the ice decreases until it is in thermal equilibrium with Triton at a temperature of -235 C. if the energy transferred by heat from the water to Triton is 471 kJ, what is the value of the waters initial temperature? (water to ice phase change)

waters initial temperature-

? · Accepted Answer

I'll assume c_ice = 2090 J/kg·ºC
and Lf = 334 kJ/kg

471000 J = 0.5kg*(2090*235 + 334000 + 4186*T)
T = 28ºC

But if c_ice = 2040 J/kg·ºC, then T ≈ 31ºC;
and if c_ice = 2108 J/kg·ºC, then T ≈ 27ºC.
Check your reference tables.

Anonymous · Answer

E-5000*(333+2.01*235) = 5000*4.186*Ti
Ti = (471*10^3-5000*(333+2.01*235)/(5000*4.186) = -170°C

This means a probable initial mix of ice and water @ 0 °C

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physics problem ?

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