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प्रश्न
Solve the following problem.
Which will require more energy, heating a 2.0 kg block of lead by 30 K or heating a 4.0 kg block of copper by 5 K?
(slead = 128 J kg–1 K–1, `"s"_"copper"` = 387 J kg–1 K–1)
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उत्तर
Given: mlead = 2 kg, ΔTlead = 30 K,
slead = 128 J/kg K,
mCu = 4 kg, ΔTCu = 5 K,
sCu = 387 J/kg K
To find: Substance requiring more heat energy.
Formula: Q = ms ΔT
Calculation: From formula,
For lead, Qlead = 2 × 128 × 30 = 7680 J
For Copper, QCu = 4 × 387 × 5 = 7740 J
QCu > Qlead, copper will require more heat energy.
Copper will require more heat energy.
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