JEE Mains · Physics · STD 11 - 10.1, thermonetry,thermal expansion and calorimetry
- JEE Mains 2022
- Medium
- Numerical
A lead bullet penetrates into a solid object and melts. Assuming that \(40 \%\) of its kinetic energy is used to heat it, the initial speed of bullet is ............ \(ms ^{-1}\) (Given, initial temperature of the bullet \(=127^{\circ} C\), Melting point of the bullet \(=327^{\circ} C\), Latent heat of fusion of lead \(=2.5 \times 10^{4} \,J Kg ^{-1}\), Specific heat capacity of lead \(=125 \,J / kg K\) )
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(500\)
Step-by-step Solution
Detailed explanation
\(m \times 125 \times 200+ m \times 2.5 \times 10^{4}=\frac{1}{2} mv ^{2} \times \frac{40}{100}\)
\(V =500 \,m / s\)
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