The melting point of ice falls by 7.5 × 1 0 − 3 K per atmosphere of extra pressure. A uniform ice block is 2.0 m tall ( ρ ice = 917 kg / m 3 , g = 9.8 m / s 2 , 1 atm = 1.013 × 1 0 5 Pa ) . If the l

Question

The melting point of ice falls by 7.5 × 1 0 − 3 K per atmosphere of extra pressure. A uniform ice block is 2.0 m tall ( ρ ice ​ = 917 kg / m 3 , g = 9.8 m / s 2 , 1 atm = 1.013 × 1 0 5 Pa ) . If the lowering of the melting point at its bottom due to the block's own weight is P × 1 0 − 3 K, find P. Give the answer to two significant figures.

TestHub · Accepted Answer

Pressure at bottom from the block = ρ g h = 917 × 9.8 × 2.0 = 1.80 × 1 0 4 Pa = 0.177 atm . Lowering = 0.177 × 7.5 × 1 0 − 3 = 1.3 × 1 0 − 3 K . This is tiny, so heat inflow from the warm surface is the main reason for melting at the bottom. So P = 1.3.

Physics - Heat & Thermo Question with Solution | TestHub

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