JEE Main20205 Sep 2020Morning ShiftPhysicsKinetic Theory of GasesActual
A bullet of mass 5 gram , travelling with a speed of 210 m s - 1 strikes a fixed wooden target. One half of its kinetic energy is converted into heat in the wood. The rise of temperature of the bullet if the specific heat of its material is 0 . 030 gram ° C - 1 1 calorie = 4 .2 × 10 7 ergs close to :
Options
- A87 . 5 ° C
- B83 . 3 ° C
- C119 . 2 ° C
- D38 . 4 ° C
Correct answer
A. 87 . 5 ° C
Step-by-step solution
As per given condition Half of kinetic energy is transferred into heat energy and raises the temperature of bullet 1 2 × 1 2 m v 2 = m s Δ T Δ t = V 2 4 s = 210 × 210 4 × 4 . 2 × 0 . 3 × 1000 = 87 . 5 ° C