KVPY2013PhysicsDual Nature of Matter
Solar energy is incident normally on the earth's surface at the rate of about 1.4 ~kW ~m ⁻² . The distance between the earth and the sun is 1.5 10¹¹ ~m . Energy (E) and mass ( m ) are related by Einstein equation E=m c² where c (3 10⁸ ~ms ⁻¹ ) is the speed of light in free space. The decrease in the mass of the sun is
Options
- A10⁹ ~kg ~s ⁻¹
- B10³⁰ ~kg ~s ⁻¹
- C10²⁶ ~kg ~s ⁻¹
- D10¹¹ ~kg ~s ⁻¹
Correct answer
A. 10⁹ ~kg ~s ⁻¹
Step-by-step solution
E Radiated by Sun array l E =4 r² 1.4 ~kW = mC ² E =4 (1.5 10¹¹ )² 1.4 10³= m (3 10⁸ )² ~m = 4 22 (1.5)² 1.4 10⁹ 7 9 10⁹ ~kg / s array