COMEDK2021PhysicsNuclear Physics
When the speed of light becomes 2 3 of its present value, the energy released in a given atomic explosion would:
Options
- Adecrease by 2 3 of its initial value
- Bdecrease by 4 9 of its initial value
- Cdecrease by 5 9 of its initial value
- Ddecrease by 5 9 of its initial value
Correct answer
C. decrease by 5 9 of its initial value
Step-by-step solution
Initial energy: E_i = mc^2 New speed of light: c' = 2 3 c New energy: E_f = m ( 2 3 c )^2 = 4 9 mc^2 = 4 9 E_i Decrease = E_i - E_f = E_i - 4 9 E_i = 5 9 E_i The energy decreases by 5 9 of its initial value.