99 Percentile Qs Bank for JEE MainPhysicsThermal Properties of Matter
A hunter fired a metallic bullet of mass m ~kg from a gun towards an obstacle and it just melts when it is stopped by the obstacle. The initial temperature of the bullet is 300 ~K . If 1 4 th of heat is absorbed by the obstacle, then the minimum velocity of the bullet is (Melting point of bullet =600 ~K , Specific heat of bullet =0.03 cal g ⁻¹ ^ C ⁻¹ , Latent heat of fusion of bullet =6 cal g ⁻¹ )
Options
- A410 ~ms ⁻¹
- B260 ~ms ⁻¹
- C460 ~ms ⁻¹
- D310 ~ms ⁻¹
Correct answer
A. 410 ~ms ⁻¹
Step-by-step solution
As per question 1 4 th of heat is absorbed by the obstacle so, 3 4 ( 1 2 m v^2 )=m s +mL aligned & 3 4 v^2=0.03 4200 300+6 4200 & v^2= 8 3 [0.01 4200 300+2 4200] & v^2=40 4200 & v= 168000 =410 ~m / s aligned