Paper 2 · Work, Energy and Power
The sun releases 1.8×10⁶ J of energy from nuclear fusion. Using E = mc², where c = 3×10⁸ m/s, calculate the corresponding decrease in mass.
A6×10⁻³ kg
B2×10⁻⁹ kg
C2×10⁻¹³ kg
D2×10⁻¹¹ kg
Explanation: m = E/c² = 1.8×10⁶ / (3×10⁸)² = 1.8×10⁶ / 9×10¹⁶ = 2×10⁻¹¹ kg
Derived from ZIMSEC Physics 5055/2 Paper 2 Theory, November 2016, Q2
