ExamBro
ExamBro
JEE Mains · Physics · STD 11 - 10.1, thermonetry,thermal expansion and calorimetry

A gun fires a lead bullet of temperature 300 K into a wooden block. The bullet having melting temperature of 600 K penetrates into the block and melts down. If the total heat required for the process is 625 J , then the mass of the bullet is __________ grams.
(Latent heat of fusion of lead \(=2.5 \times 10^4 \mathrm{JKg}^{-1}\) and specific heat capacity of lead \(=125 \mathrm{JKg}^{-1}\) \(\left.\mathrm{K}^{-1}\right)\)

  1. A \(10\)
  2. B \(20\)
  3. C \(5\)
  4. D \(15\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(10\)

Step-by-step Solution

Detailed explanation

\begin{aligned} & 625=\mathrm{ms} \Delta \mathrm{T}+\mathrm{mL} \\ & 625=\mathrm{m}\left[125 \times 300+2.5 \times 10^4\right] \\ & 625=\mathrm{m}[37500+25000] \\ & 625=\mathrm{m}[62500] \\ & \mathrm{m}=\frac{1}{100} \mathrm{~kg} \\ & \mathrm{M}=10 \text { grams }\end{aligned}

Same subject
Explore more questions on app
From JEE Mains
Explore more questions on app