CSEC Physics · May/June 2011 · Paper 2 · Question 6(b)(ii)

A gram of living plant material with Carbon-14 decays at a rate of about 16 disintegrations per minute. When the plant dies, the Carbon-14 decays, with a half-life of 5 600 years. A gram of the dead plant is found to decay at about 1 disintegration per minute.

The mass of the sun is lost at the rate of 2.0 × 10⁹ kg s⁻¹. If the speed of light in a vacuum is 3.0 × 10⁸ m s⁻¹, calculate the power output of the sun in kilowatts.