Elasticity, Thermal Expansion, Calorimetry and Heat Transfer: Specific Heat MCQ

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Specific HeatMediumQuestion 30847

Question

A 100 g copper block (c = 400 J/kg·K) cools from 100°C to 30°C in water (c = 4200 J/kg·K) initially at 25°C. Neglecting heat loss, the mass of water is approximately:

A
133 g
Correct
B
67 g
C
270 g
D
54 g

Correct answer

133 g

Explanation

Heat lost by copper is $0.1×400×70=2800$ J. Setting this equal to $m_w×4200×5$ gives $m_w=0.133$ kg = 133 g.

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